I was given a regular size rooster who happens to get along with my bantam hens very nicely. my question is well there be any issues with him mating with my bantams?
Probably not. Part of the mating routine is that the hen squats before he mounts her. That way his weight is passed into the ground through her body, not just her legs. Roosters are typically heavier than hens of the same breed anyway. The more weight difference the more the risk but many people have full sized fowl roosters in the flock with bantam hens without problems.