Way of the Land is already a powerful virtue, even without giving Magi a +3 to study from Vis.
It gives you +3 to most rolls in the area, including Combat rolls, which is by itself a huge boost, and it also applies to some Casting Scores.
As I said, you can interpret it your way at your table, I won't stop you.
But if it involved interacting with the land, why would you be able to do in the Lab, where it's usually far from the land it was harvested from? Otherwise, this quote from the core book, would be wrong:
"Studying from raw vis does not require a Hermetic laboratory; it can, in principle, be done anywhere. Most magi do study raw vis in their laboratory, though."
Why would most Magi study it in their lab if they need to interact with the land to study Vis?
Vis may come from the land, but if you harvest it and study it in your lab neither you nor the vis is involving the area any longer, let alone directly involving it.
Like I said earlier, one could make a case that you get the bonus if you study the vis where it is found in the area, without harvesting it first. Not feasible for all vis sources though, since in some cases the vis is only available there for a brief period of time and has to be harvested if you want to make use of it at any other time. Possibly also if your lab is situated right in the area - not inside a large covenant complex.
But, in general, studying vis does not and should not benefit from Ways of the Land.
Why would a magi study out of the comfort of their lab? If has all the magi's cool stuff, any protections the magi may have cast, a stuffed crocodile perhaps, it's just a nice place to be.
There is absolutely no need to interact with the land when studying from vis, however, I'm going to suggest casting a pilum of fire also isn't interacting with the land, but the +3 will apply for the person with "way of the land".
Someone with "Way of the land", who has a mythical connection of the land, may want to study with vis while wandering the land.
Depends on who you cast the pilum of fire on. If it is on an inhabitant of the land in question you get the bonus, since that is definitely directly interacting with an inhabitant of the area.
If, on the other hand, you are casting the pilum on a stranger just passing through the area I see no reason to believe you get any bonus from Ways of the (Land), since it isn't a roll directly involving the area or its inhabitants.
There are only a few things that the rules tell us that affect Study from Vis:
Study Bonus
Study Requirement
Aura
Free Study
Unimaginative Learner
You can decide for your troupe that Ways of the (Land) is also appropriate, but that's a house rule, and not supported by the rules.
Any Magi can study away from their Lab. Few do so, because they get a better Aura. Those who do study in the wild, are usually those with Study Bonus/Requirement. anything beyond that is a house rule.
Yes, I believe it is. Study Bonus/Requirement does not require direct interaction with an example of the Art, only observation. The most we can argue is that it might involve direct interaction.
This particular argument is a bit weak, because combat rolls are explicitly benefited by Ways of the (Land) regardless of your opponent. The reading is that combat is indeed something active, that relies on your understanding on your surroundings. You stabilize your footing, use the things around you, change your position, etc.
There's no reason for any of those to be untrue for spellcasting. I'd expect, in a similar manner to a combatant, the magus to change his position to get a better view of the target, mind where he is stepping, avoid direct sunlight to his eyes... In essense, interact with the terrain.
While studying from vis, however, there's no assumption of interacting with your ambient in any meaningful way. That might be simply because we have no concept about what "studying from vis" actually is. Is it just meditating in the presence of raw vis? Is it trying to channel it through your body? Is it using the vis to incur changes in your surroundings and taking notes about those changes? We don't really know. It could even e something different for each magus.
Perhaps the focus of this should be shifted. There's nothing that requires one to interact with the area or inhabitants while studying from vis. But is there anything that prohibits it?
There are examples of this, however. Study Bonus and Study Requirements are clear example that interacting with the environment can be a part of vis study. Other examples include Significatos, which is pretty much all about interacting with a phenomenon in a specific area. Sahirs studying from Djinns using the TC&C ruleset (as opposed to the HoH:S ruleset, which implies teaching), are also studying them as significatos. Significatos use the same exact rules as studying from vis, except you don't spend pawns, because the phenomenons your pawns are consumed to produce already exist close to you.
Now mind you, there are reasonably good reasons not to allow Ways of the Land not to apply to vis study rolls. On the other hand, I'm not sure it makes sense to refuse to apply it to someone who had Ways of the Volcano and study bonus going to a volcano to study Ignem for the season (Mountains = Terram, Cities = Corpus or Mentem, Forest = Herbam/Animal, etc.). And I don't think I could find a reasonable way to refuse the bonus to a roll for a significato that is natural to the area the character has a Way of the (Land) for, that didn't sound arbitrary.
Are they indeed?
The virtue says
"You get a +3 bonus to all rolls,including combat, and Casting Scores that directly
involve that area and its inhabitants; mundane, magical, or faerie."
Does all combat directly involve the area? I am not convinced it does.
I also note that it talks about mundane, magical, and faerie inhabitants. Nothing about divine or infernal inhabitants.
If you have ways of the Forest, I'd say that moving about fighting and using trees as cover is probably what you're doing. If you have ways of the Desert, you're probably trained to throw sand to blind in a moment's pinch, and your footstep on shifting dunes is more stable than your opponents. The bonus also applies to its inhabitants. If you have Ways of the Forest, and you're fighting a forest animal, human, magical beast, faerie, etc. than you are involving the inhabitants.
Someone with Study Requirement cannot Study Vis except when studying in an area that is suitable for the Art of the Vis. But it doesn't say that he studied the environment, he just needs to be in it's presence.
Someone with Study Bonus can Study Vis in his lab, but he likely won't get the bonus, unless his Art Score is low. But even then, the argument for Ways of the Land is a bit flimsy, in my opinion, because Study Bonus calls it out specifically. And you're likely using a lower Aura than your covenant, so you're already missing out.
The errata for Ways of the (Land) says: "You get a +3 bonus to all rolls, including combat, and Casting Scores that directly involve that area and its inhabitants;..."
It study from vis a roll? It is. Is the area directly involved in a check when the area is required for the check, or when being in the area provides a bonus to the check? Are its inhabitants involved in the check when you're studying Animal, Corpus, Mentem and you literally need them or you fail for study requirement? I'm hard-pressed to say the area or inhabitants aren't involved in those instances. If you merely sit in a forest, but you're studying a collection of rocks you brought from the outside hoping to benefit from Ways of the Forest, that's a different case entirely.
It can be a fair argument to talk about rules as intended versus rules as written - was this scenario considered in drafting the virtue? Different troupes will have different calls here. I don't expect to change your mind about RAI, and if at your table, you say it's not RAI, fine. But I don't think you can reasonably argue the RAW is fully on your side here, even if the RAI case can be a pretty solid one. I don't think it's that unbalancing to say the +3 bonus applies to some study vis rolls. How many art are you going to claim the bonus for, anyway? Possibly 2 or 3 out of 15? And only on vis study which is far less optimal than book learner is typically? This kind of benefit doesn't fundamentally break the virtue. Many magi ignore vis study until at high levels anyway. I don't see a problem to give a benefit to studying high level Herbam to a magi with Ways of the Forest. Actually I find it thematic.
It is very clear to me that this bonus is not RAW nor RAI. I think this is a very reasonable change to houserule, just like applying Puissant Craft to all crafts, or allowing a nongifted Strong Faerie Blood with Magic Theory to act as a lab assistant with a Merinita in a faerie aura.
If I was directly involved with this game, I would probably argue that the bonus should only apply to vis in its natural form and if tied to the land. I wouldn't want Ways of the Forest to give a bonus to studying Ignem vis drawn from the left eye of a dragon, I wouldn't want to tie it to 'if study bonus would apply', because then you can double-up on bonuses if you have Study Bonus as well.
In short, I don't think it applies or should apply. However, if you want it to because it seems cool, then that's awesome. I'm not even going to say 'oh its your table do what you want', because that's a very reasonable house rule. But I think it is very much a house rule, not a clarification.
You already can triple dip right now with Elemental magic, book learner and study bonus combined. I don't think it's a big issue here, especially if you only allow the bonus from Ways to apply in a restricted way.