Can also vary greatly depending on the time of day you get in. If you land after dark, the buses will sit there until they're 3/4 full, then leave. We've experienced that on our past two trips (March and August).
Also, if you get your own bags first, add at least 30 minutes, because MCO is not known for their swift baggage handling capabilities.
Touchdown to the gate, in Orlando, is a long trip. 5-10 minutes. And getting off the plane varies by where you're sitting, obviously.
As for just the bus ride, it will be between 35-45 minutes from the time your bus leaves until you get to your resort.