Well... you can put the elfs near the BONUS_FRUIT_OF_YGGDRASIL, which is in the same tile as the Yggdrasil.
Also every civilization should stay away from BONUS_MANA_DEATH, which indicates Barbatos lair.
Malakim should also have FEATURE_FLOOD_PLAINS, FEATURE_OASIS and BONUS_INCENSE (to help religion...)
Elohim should also be near BONUS_INCENSE
Khazad and Luchuirp might be near BONUS_GEMS, due RoK
Lanun near BONUS_PEARL
Amurites and Sheaim near BONUS_REAGENTS
Also every civilization should stay away from BONUS_MANA_DEATH, which indicates Barbatos lair.
Malakim should also have FEATURE_FLOOD_PLAINS, FEATURE_OASIS and BONUS_INCENSE (to help religion...)
Elohim should also be near BONUS_INCENSE
Khazad and Luchuirp might be near BONUS_GEMS, due RoK
Lanun near BONUS_PEARL
Amurites and Sheaim near BONUS_REAGENTS