You need to be waiting for youR DME bus fifteen minutes prior to its departure.
You need to, or it's strongly recommended that you, allow another fifteen minutes for last minute bathroom runs, picking up your checked carry-on luggage, etc.
You could need to wait twenty minutes at the park if you just missed a bus.
That's fifty minutes, not counting the actual ride or other stops (if you're on a shared route, or if your resort has multiple bus stops).
2:30