Although tipping at all-inclusive resorts is considered to be an optional gesture, you might want to consider tipping those who are providing you with a personal service. This includes bartenders, wait staff, housekeepers, tour guides, and masseuses.
They are the ones transforming your stay into a luxurious experience, which is definitely worth a reward. By tipping them, you show your gratitude and encourage a better quality of the service in the future.