Any skill that was below GM before taming can be trained to GM
Skills that are above GM are a little more complicated. The post-tame cap on those skills is whatever the skill was pre-tame * .9.
so a pet with 119 wrestle pre-tame will have a post-tame cap of 107.1
EDIT
One thing I'm not sure of... if you beat the creature's health down, that may impact the skill cap... I know beating pets up before taming them can impact the skills on the pet post-tame, but I'm not sure if it impacts the cap on the skills of a critter post tame.
You can peace tame reptalons easily with 120 music/peace, so you don't need to beat them up (actually, the only creatures you really need to beat up to tame are the ones that must be beaten into submission)