I say yes (am I the first one to explicity answer that? Good for me!).
Yes, because:
The same could be said about any other situation where Premonitions kick in, or for any other character concept. So you want to be a diplomat with Premonitions? No no no, better pick Puissant Intrigue, Affinity with Folk Ken, Piercing Gaze... that huge set of options is there for anyone.
If a character gets a virtue, he is expected to get a benefit from it (also if a player asks for that, he is already anticipating to have fun with that, and this is a game, it is supposed to be fun). Are there many virtues that he can use to be better at what he does? Well, then he can pick and choose as many as he see fit (and can afford). Is there any reason he shouldn't pick the virtue if the player wants it? Obviously not. Isn't to expect that a warrior with premonitions would have some advantage in combat? I think he should, because that's his thing, and his virtues should apply to his concept. It is frustrating when you answer "oh, yeah, so you got Premonitions!, quite cool virtue for your legendary swordsman. It's such a shame you are only going to use it when you are not in a fight".
Before combat starts, roll Premonitions against 6+. For each 3 points of success you roll in advance one stress die. Then, each round during combat, before any roll is made, you can pull off one of your "foreseen" rolls on whoever is rolling. I'd even allow to reuse the skill by spending a confidence level: spend one, and you make another roll, and can anticipate more rolls.
In this way a character with Premonitions do have an advantage in combat. It is not a killing advantage (it is not like you get a 12 on Premonitions, anticipate two rolls, get a 2 and a 9, and say "ok, 9 is my attack and 2 is the defensive roll of my target", because you can only change one roll per round), he is not going to win the fight just because a Premonitions roll went good. It is not slowing the game because you are actually moving rolls before the fight (as soon as he starts pre-rolling the player is going to start thinking things like "an open ended roll! That's going to be my first blow"). And it have to happens fast because the player needs to call to assign the roll before the roll is made, so if you are playing fast then he is going to answer fast as well.