If you make it, it would be very close, and that's if you don't have any other stops and don't bother going to your room.
Figure, you get on the bus and leave around 5:30 (best case). You get to Pop by 6:00 (best case). You get checked in and are out to the bus stop by 6:30 (again, not going to your room). Bus comes right away and gets you to Epcot by 6:45. By the time you get into Epcot it's 7:00. That would give you just enough time to walk over to World Showcase.
As for Boma, even less of a chance. Your best bet would be to get an Animal Kingdom bus, but the park will already be closed, so I'm not sure if they'll be bringing guests back to the park. Then you'd have to get off at AK and take the AKLodge bus.
8:00 might be possible but I wouldn't plan on it. I would probably opt for a dinner at Downtown Disney or Boardwalk instead.
Of course, you could always take a cab to either Epcot or AKL, and you should make it.
General rule of thumb, always give yourself at least 3 hours leeway from the time you land in Orlando until whatever you have planned first.