I have asked that question at the Hotel where we stay as they put a 10% "hotel service charge" on all bills. I asked how that money and tips were handled. I was assured, and had it confirmed by other employees, that all the "service charge" money is split between the behind the scene workers who do not normally get tips - gardeners, laundry people, bakery workers, dish washers, back office employees, etc..... All the tip money goes to the server who served you, whether it is cash or put on a credit card. It is up to the server to split the tip with cooks, bus boys etc...