On my last RCI cruise, the waiter in the Windjammer inferred that the tips were shared. It was my understanding that the waiters rotated turns in the Windjammer. Those in the dinner room shared with those in the windjammer. Maybe 2 waiters were assigned to a section and each week they shared.
The waiters in the dining room at dinner pull extra duty in the Windjammer and other venues during the day. The tips they receive from the dining room are essentially "spread out" over all their duties. Is that what you are asking?