Yes, buses run for one hour after park closing. However, you might want to double-check the hours for RFC (if you haven't already). I was at Animal Kingdom last Saturday for the Expedition Everest Challenge. The park closed at 5pm that day. My boyfriend wanted to grab a drink at RFC around 7pm while he was waiting for me to finish the race, but RFC was already closed. I don't know if that was because of the race or if RFC usually closes around park closing time.