This entry is from Club Med's own FAQ, which reveals that this resort thing is a bit creepier than I knew it to be:
What does GO and GM mean?Ooh ooh ooh! Sign me up for the pennyfarthing rides and life-sized chess game, Number 2!
All members such as yourself are GM´s, short for gracious members. Your sports instructors, hosts and hostesses, chefs and entertainers are GO´s, or gracious organizers. Everyone lives in the Village, a self-sufficient vacation setting headed by a charismatic Chef of Village.