No, not according to the rules, or in this game. However, dominated NPCs, or even animals and monsters, become part of your party and are controlled by you and do receive XP.
Dominate monster may be bugged, however. It makes the creature join the group, follow me around, but nothing more. No combat commands (right click options don't happen), and damage from any source turns it hostile. And it keeps repeatedly rolling will saves over and over. Unless I'm missing something I should maybe make an official bug report?
Heh, General Ghoul was here a few days ago - let's hope he sees this Good question, btw - I'd say, "no..." but I'm not 100% sure. (Unless the familiar was part of the party of course).
The only way that a familiar gains xp (and shares with the group), is when you ask a wizard (or sorceror) to take his familiar out of his backpack, and then ditch the wizard.
hellblazer, General Ghoul answered your original question in the second post of this thread. But just to clarify if you still aren't sure: Only critters that occupy any of your party's NPC slots receive a share of your party's XP (except any (wizard's and/or sorcerer's) familiars that have been released out into the party as a controllable NPC (and whose portrait is added to the row of portraits at the bottom left of the screen) - familiars never receive any XP (unless you cheat by doing what nyarlathotep stated in an earlier post of this thread)). If you successfully cast Dominate Person or Dominte Monster on a legitimate target, then it will cause that target to join your party as a NPC (provided that your party has an empty NPC slot) (where the target's portrait is added to the row of portraits at the bottom left of the screen, which displays all of the critters in your party that receive a share of your party's XP (except for familiars)). That is, any dominated people or dominated monsters WILL receive a share of your party's XP because they can level up just as your PCs and any NPCs in your party can level up. If you have any druids or rangers who use their class ability to call an animal companion, then those animal companions do not receive a share of your party's XP. If you have any wizards and/or sorcerers who use their class ability to call a familiar, then those familiars do not receive a share of your party's XP (unless you cheat by doing what nyarlathotep stated in an earlier post of this thread). Any animals that your spellcasters summon using the spell Summon Animal # and/or any monsters that your spellcasters summon using the spell Summon Monster # do not receive a share of your party's XP. If you successfully cast Charm Person or Charm Monster or Charm Animal on a legitimate target, or if your evil cleric successfully commands undead, then that target or those commanded undead become followers. Followers do not receive a share of your party's XP. You can't control followers during combat (except for familiars that have been released out into the party as a controllable NPC (and whose portrait is added to the row of portraits at the bottom left of the screen)). In the Circle of Eight Modpack, you are allowed a maximum of 10 followers at any given time during the game. I suspect that summoned monsters/animals, and charmed people/animals/monsters, and commanded undead, and (druid's and/or ranger's) animal companions, and any (wizard's and/or sorcerer's) familiars that have been released out into the party as a controllable NPC (and whose portrait is added to the row of portraits at the bottom left of the screen) all count towards the limit of 10 followers.