[Edi]

Hmm, if the fountain bonus is listed as +10, then it must have been said on the forums sometime in the past. The +3 for the melqart is confirmed by Kristoffer.

The dousing bonus is +x levels of blood magic for purposes of finding bloodslaves. So a fountain with B9 would hunt for bloodslaves like a regular blood mage with B19. Melqart gets the bonus also to blood sacrifice in addition to hunting.