as shauna said, assuming you get a safe plant in bonsai form you will be fine
HOWEVER, take note that bonsai's do have some special care requirements. I have no experience with them, but I would be wary of anything that may conflict with the chameleon (off the top of my head, I would think that the bonsai would drown from too much water?)
not saying its not doable but there may be more to it than a typical plant....the bonsai experts can hopefully clear that up