Just to make clear, your options from WL to Fort Wilderness are:
1. Walk, but dark at night, takes about 20 to 25 minutes.
2. Bus, there are two busses that travel the TTC WL FW circuit, Boone and Crockett. I believe it is the Boone bus that runs TTC-WL-FW (thus take it going); I believe it is the Crockett bus that runs TTC-FW-WL (thus take it back from FW); in any event check on the precise routes of the two busses when there. Trip takes 5 minutes one way.
3. There is a boat that runs the FW-WL-Cont circuit; you can take that but may go to Cont first.
Sometimes the boat to and from MK goes to both WL and FW. Thus, you may also be able to take that one. In any event the boat ride can be anywhere from 5 minutes (if you go direct) to 20 or more if you have to go somewhere else first.
All of the above methods deliver you to (and take you from when departing) the main activity area of FW where Pioneer Hall and Hoop Dee Doo are so you do not need to take the FW internal bus.