There are a few camping spots in Bunyip State Forest. Gentle Annie, Nash Creek with Dyers and Kirth Kiln having the best facilities.
Dyers has a drop toilet and a running creek and is right in the forest.
Kirth Kiln has a toilet and running creek, this area is north west of Gembrook.
A Parks Vic or Rooftops map will show you how to get to these.
Nick