*disclaimer: I'm FT, so things MAY be different for CPs*
When I was at the Polynesian, I was a Concierge cast member. (My official title was Concierge H/H, compared with the Front Desk folks, who's title is Resort Guest Service H/H). I went through the front desk training, did a few weeks on the desk, then went back to DU for the concierge training, and had my OJT at the resort. I started off working the concierge desk in the Great Ceremonial House, and after a while, I got trained for the Club Concierge desk. Same sort of stuff, really, just a different location.
I also got trained in the back office roles (Operations Support / Room Assignment), and once I was trained there, that was pretty all I did.
Around the time that I transferred, they started training all the club level concierge cast to work in the lounge as well. (Previously, there were lounge folks, and desk folks, and not much overlap)