Yea, it seems from my combat logs that our pets damage is unaffected by target players resilience, and if you stack a bunch of mastery, pull out the fel guard, axe toss and whirlwind, its almost instakill. At least this is my theory, when my pet strikes another player even a player in full vicious, it says my pet his for x damage, 0% resisted. And it hits roughly as hard as it does on raid bosses.