I am a little confused. For the bolded part, are the gymnasts at different levels? Did your dd not go because of her level or because she was injured/you chose not to go? Also, are these fees for travel that has already taken place (as in - you owe more due to additional expenses we didn't anticipate) or for the upcoming season?
As for the specifics - alcohol, family travel - I don't think there are any books on the law for this. There are laws for tax deductions on the business but that's a different situation. This is no different than a gym charging outrageous tuition costs. It's their company. They can charge what they want. If it's too extreme, the customers will rebel.
Having said all this, I don't have a problem with a gym owner choosing to give their coaches (or him/herself) extra travel reimbursement for some family travel. I mean, these coaches are away from their children so much during meet season and even throughout the year. Letting them have a little family time while at a destination spot or two is a small price to pay to acknowledge this sacrifice. And really, it's either that or the owner pays the coaches more to account for this and then tuition is increased. Either way, the customer is paying for it.