There is a general consensus among wedding etiquette writers that no matter where a wedding is held, the guests pay for their own accommodations. This would hold true whether your wedding will be in your hometown or at a destination such as in the Caribbean. Of course, with a destination wedding, this may feel a bit different, as the guests are also going to be paying larger travel expenses.
It is, however, proper etiquette for the bride and groom (or their parents, depending on who is throwing the wedding) to pay for the rooms and other incidentals of the bridesmaids and groomsmen. The wedding attendants are responsible for their own travel expenses, such as airfare.