I'm sure some of the resort vets will chime in here, but I think you're cutting things WAY too close. First of all you're assuming that your plane will arrive on time. Then you are hoping to get from the plane, through the airport, onto the bus and to the resort in less than 90 min. Then you hope to get through the waiting line, check in, drop off your carryon bags, get on a bus, get to Epcot, and walk through to WS(?) in half an hour????? Very unlikely.
If you can, see if you can change your ADR to a Dinner reservation.