I want to repair a spot in my bathroom ceiling where the paint has started
to bubble due to condensation. Even with the vent fan on, it seems to be
too damp in the room.

My plan was to scrape the area so that it is flat and then patch with
drywall compond before painting. My concern is that due to the nature of
bathroom and dampness, won't the drywall patch eventually bubble-up again
and cause the same problem?

Do I have to buy a special mixture of patch for bathroom?

Thanks