I haven't tried using Pet on a Spitting Raptor. I mostly like Spitting Raptors for the ability to remove armor, and while a Pet's melee attack gets buffed, their ranged attacks are not improved.
I've tried using a Pet Emerald Tegu, and while it is certainly functional, I prefer Timber Wolf, even with just the core set. With the addition of undead, Iron Golems, and Devouring Jellies, Emerald Tegu has become more situational.