So I have a bear-dog animal companion with only a bite natural attack, then she adds 1.5 times her Strength modifier to damage rolls with it. She has Power Attack both for extra damage and as a prerequisite for other combat feats (oh, right : she also has the very convenient Clever Critter feat to no longer be limited to a small list of basic feats).
Power Attack gives a bigger damage bonus to two-handed weapon attacks and primary natural weapons that give 1.5 times your Stength modifier to damage rolls. But some feats that require Power Attack sometimes mention a greater benefit for attacks performed with two hands but not primary natural weapons.
Prerequisites: Str 13, Power Attack, base attack bonus +1.
Benefit: When you are wielding a two-handed weapon or a one-handed weapon with two hands, and using the Power Attack feat, you do not suffer Power Attack’s penalty on melee attack rolls on the first attack you make each turn. You still suffer the penalty on any additional attacks, including attacks of opportunity.
Prerequisite: Str 13, Power Attack, base attack bonus +1.
Benefit: When you are not mounted and you use the charge action, a successful attack deals an additional 2d4 points of damage. If you are using a 2-handed weapon, or a 1-handed weapon in 2 hands, you instead deal an additional, 3d4 points of damage.
Prerequisites: Str 15, Power Attack, base attack bonus +1.
Benefit: When you hit a creature your size or smaller with a two-handed weapon attack modified by the Power Attack feat, you can choose to push the target 5 feet directly away from you instead of dealing the extra damage from Power Attack. If you score a critical hit, you can instead push the target 10 feet directly away from you. This movement does not provoke attacks of opportunities, and the target must end this move in a safe space it can stand in. You choose which effect to apply after the attack roll has been made, but before the damage is rolled.
Then would my bear-dog get the benefit of two-handed attacks with her bite with those feats, or only two-handed weapons benefit from them ?