I have been a GM of D&D eberron for around 2 years, and there is something that I always ask myself:
Are Valenar elves and AerenalAereni elves different races of elves in terms of gameplay?
As I don't know, I let my player choose between wood elves and high elves as subrace (as drows are in Xen'drik and so they are not involved in this question), but for me it would be logical that Valenar = wood elves and AerenalAereni = high elves.