I had some leaking in this area but was lucky enough to catch it before any water damage to the bulkhead occurred. All I can suggest is that you poke small holes in the veneer and inject adhesive. Then press the veneer onto the bulkhead with a flat piece of plywood and a pole between the plywood and the nav station (or galley as the case may be). You may want to wax the veneer to prevent the adhesive and plywood from sticking to the surface. This will leave some small holes in your veneer but should get it reattached. I don't have any suggestions for what to do with the adhesive holes.
This is the best I can think of without peeling the entire veneer panel and replacing it. Good Luck.
