My thinking on this is that if the crew aren't interested enough (or, more likely, are too busy) to look up on the manifest who the top tier members on board are then they probably won't appreciate you thrusting it in their face. I never get upset about not getting anything extra for being Diamond, and I only ask for "something special" if the ISM/Purser has specifically greeted me and asked me if there is anything s/he could get me.