Hi Michele,
All the answers you could ever want about the Barceló resorts can be had at the
Unofficial Barceló Maya site.
But to quickly answer your questions:
Yes, they do charge extra for some premium booze. Certain tour operators offer an "upgrade" that includes the premium stuff. Transat Vacations in Canada is like that. Not sure if there are others.
I can't recall if there are rooms with jacuzzis. There are currently two basic sections at the Barceló: the original section with the Beach and Caribe and the newer section with the Colonial and Tropical. The Palace should be open in a few months. We've stayed in both sections (Beach in 2005 and Colonial in 2007) and are returning to the Beach in October.
The main differences are in the dining choices. Staying in the original section, you will have access to two ŕ la carte restaurants (Mexican and Spanish). The new section adds four more restaurants (Japanese/Thai, Mediteranean, Steak House and Italian) for a total of six you have access to. Staying in the original section you get to visit the ŕ la cartes twice per week, the new side bumps that up to four dinners per week. The new section has A/C in the buffets, the original does not. You only have access to the A/C buffets if you stay in the newer section. Other than that it's pretty much all the same. Regardless of where you stay, you can access all the pools, beach restaurants, bars, theaters, disco, shops, etc.
Hope this helps
