The reported average time from airplane to resort is 70 minutes. For that leg of the trip, no one has reservations for an exact bus, so it's not like buses are waiting for specific individuals or flights. Buses are supposed to wait around no more than 15 minutes before shoving off. Of course, there's no guarantee that there will be a bus waiting for you to board.
I had 2 great experiences with DME. First time it was 63 minutes airplane to resort drop-off, and the next time it was 56 minutes airplane to resort drop-off.