Hello Jo,
They really like to throw new names around, don't they? Here is what I think - but could be corrected.
Grupo Mayan used to be their corporate operating name. When they expanded, they changed the Corporate Operating name to Grupo Vidanta which it still is. However, the Grupo Mayan name hangs around and is used by most interchangeably.
I believe they recently invented a new name, Vida Vacations Club, that is a marketing name and web access to all the Resort properties. At one time, I was told that Grupo Mayan is a sub operating organization under Grupo Vidanta that oversees the lower level properties (Grand Mayan and below).
In reality, I don't think anything has changed. You still have the subcontracted sales people that do the high pressure sales for initial sales, and the member Services people who work for the company and administers the contracts. I also believe that the folks who do the Upgrade presentations do work for the company - but different people from the Member Services folks.
This is all logical conjecture on my part.
Mike