Ambitious Schemer Seduction and treachery are tools for advancement in drow society, even for the martially inclined. Drow with this racial trait may choose either Bluff or Diplomacy as a class skill, and gain a +2 bonus on such skill checks. This racial trait replaces keen senses.
So, +2 on Dimplomacy AND Bluff, and one of them class, or +2 on ONE OF THEM, and it is class skill now? Can not understand.
You choose either bluff or diplomacy. It becomes a class skill, and you get a +2 bonus on the particular skill (only 1, not both).
Claxon is correct. The ability states "or", so you only get to select one.