The LAST thing you want to do is take a bus from DS to BW. We did that a couple of times and it was, by far, the worst! Each time, they would cram you in and then stop at each of the Epcot resorts and BW is last. To make matters worse when we stopped at BC and YC, they just didn't drop off guests, they also loaded guests going to DS so that they did not have to go around again
That was so idiotic.