Instead of a bonus, I like to think of it as a penalty. Each week, your players receive a set amount of training based on your training choice and level of trainer. That training is then penalized based on player height, age of the trainee and the elastic effect/CT, if applicable.
For a 7'3" player, there is virtually no height penalty for inside skills. On the other hand, he will be docked 60% of his training on OD JR and HA, then 30% on DR and PA (according to CoachParrot).