Every single person arriving into MCO (be it on a plane, car, taxi, or yak) is entitled to ride the DME bus. Every single airline passenger can use DME upon arrival. You just need to make your reservations beforehand, then tag any checked bags with the yellow tags you will be sent. When you get to MCO, just head directly to DME, and your bags will be taken away as well.
There still seems to be a ton of misinformation out there regarding DME...and that is surprising. 'Participating airlines' is only an issue upon departure from your resort, heading back home. And even if you aren't flying home on a 'participating airline' you still get to use DME, for yourself and for your luggage. 'Participating' only involved RAC (remote airline checkin) which allows you to checkin for your flight at the resort, hand your bags off and get your boarding passes issued. You don't even have to be using DME to take advantage of RAC...just be flying out on one of those 'participating' airlines.
Call, get your reservations made for DME. You will get a packet about a month before you fly. Put the yellow luggage tags on your checked bags. Say goodbye to your bags at your home airport and board your plane. When you get to MCO, head directly to the DME area, where you will board your bus and head to your resort. Your bags will be taken care of by DME on another level. The airline you arrive on has absolutely no bearing on the ability to use DME. Of course, if there is a reason you want your bags with you, just don't tag them, and go to baggage claim and get them yourself and then take them to the bus with you. But that is wasting one of the great things about DME.