Fort Wilderness is at least 4 times larger, maybe 8 times larger than OKW. It's is over a mile square, so an internal bus is necessary to get to all of the major areas within the Fort. Buses run about every 5-10 minutes, to 3 different routes/locations within the Fort. At the end of the "Outpost" line, you then wait for a regular bus to take you to a park or at the "Settlement" line, you walk to the marina for the boat to MK.
OKW has the same bus for parks and internal transportation. You only really need to get to the Hospitality House area internally, which could be 2, 3 or 4 stops away from your stop, That could take anywhere from 10-30 minutes depending on how many people are boarding. After the final stop, you immediately leave for a park.