My understanding is that you can use the tags going to your resort (and they will magically appear in your room...no need to pull them yourself), but on the return flight, you have to handle your luggage...ie...put it on the bus and then go through the check-in line at the airport.
There has been a buzzz about SWA becoming a participating airline for the trip back, but I have not seen anything official yet.
I hope that if any of this info is incorrect, someone will correct it, as I am flying SWA for our June trip.
Lynn