I dont play feral so i have no idea how that compares to agi but check it out in a BG and see if scales weird like +weapon dmg does.I was swapping out shoulders with the old Hodir enchant and it does look like 1 AP = 1 damage. The 4 and 5 point Ferocious Bites gained 3 damage for 2 AP. But that's just tooltips too. The AP didn't translate to dots on the tooltips, only direct damage. Haven't done any testing though.
this ^^1 AP = 1 str/agi
1 SP = 1 int