I think when it comes to bench players looking at one season can be misleading. The career stats of a guy like Hanahan is probably more indicative going forward even as bad as his power was last season.
Career wise his OPS sits at .665, and he's generally played very good defense. Does that make him an elite bench player? I'd say it's pretty hard to call him that. He's a guy with a glove and can handle the bat enough to not be an auto out.
He's a fine bench player. I don't think there's a whole lot else that needs to be said about him.