Aviv,
BPDU's will pass over the mesh link if you have stp enabled on the Wired Switch.. in order for BPDU to cross the mesh.. (not a good idea as it does take up mesh bw/broadcast) . you don't have to do anything. if you want to stop bpdu's from crossing the mesh you enable STP on the GE port of the AP.. its kind of backwards when you think about it.. however , by enabling STP on GE port the AP is smart enough to stop the bc from going out the Radio interface..
