[quote=@December]
Question: Am I allowed to make my air bending mentor a descendant of Tenzin and therefore be named after Tenzin? I figure he'd be either Jinora or Rohan's grandson.
[/quote]

All air benders would be a descendant of Tenzin, since he's the descendant of Aang, [i]the last airbender[/i], there's literally no other route for ancestry there. :p