Looking at the rules for enchanting items, and the rules for multiple laboratory activities, that is indeed not an exception to the regular rules.
If your Lab Total is double the level of the power, you can invest the power in one season. (ArM5 p99)
You can do multiple lab activities in one season, if they are all of the same type, all use the same Technique and Form, and each can be done within a season. Then you just apply your Lab Total to the combined required levels (ArM5 p102)
Those two rules in combination should give exactly the result described in the third "exception" in the familiar bonding enchantment rules.
(If one wants to be really picky, the rules for enchanting items don't say anything at all about investing multiple powers in one season, so one would have to look both at the rules for enchanting items and at the rules for multiple lab activities to figure out this can be done - but it still doesn't look like an exception to what can normally be done when enchanting an item.)
Most of the things later in the section on Empowering the Bond are not exactly exceptions to the rules for enchanting items, but rather things that are not touched upon at all in the rules for enchanting items (since those never mention anything about familiars or familiar bonds).
For example, that when a power is invested in the bond, mage and familiar each take on some minor characteristic of the other. Not part of the regular rules for enchanting items, but not changing anything said there either.
As it is, one could easily get the (false) impression that those are all part of the regular rules for enchanting items, since they are not part of the list of exceptions.
My suggestion is to change "with five exceptions" to "with some changes", followed by an unnumbered list of the five four actual changes from the enchanting rules.
So instead of "First, there is no limit to the number of powers which may be invested in a familiar." you would have "- There is no limit to the number of powers which may be invested in a familiar." And so on.
While in some ways less precise, I think that would actually be less prone to misunderstandings.