We were just there last week and we used the bus system to go to Ft. Wilderness twice. Once for Hoop Dee Doo Revue (which is a ton of fun by the way) and once for the campfire. The busses work great and we were there within a few minutes. I honestly didn't even know you could walk there so we never tried.
Once you get to the main area of Ft. Wilderness (the Settlement) you take another bus to the campfire (the place is huge). The campfire was okay - I was expecting something similar to Vero's campfire, which it is not. Getting a bus after the campfire to go back to the Settlement was another story, that took forever. We must have waited 1/2 hour.