I'm not sure there is a bug... Many bonus are available if you to rest to Caed Nua and in compensation, the prostitutes give a "prestige bonus" (sic) to the stronghold.
Recently I've played the 1st Spellforce... The 1st time my reaction was : "My God ! This game is really hard !".
Then after finish it 3-4 times : "This game is easy, too easy...".