I've become so frustrated with this on NW's end (as WP Silver) when flying on CO, that I recently asked CO to match my status so I could start using OnePass instead. I realize that the systems are different and it's a difficult task for either party, but NW CSR's have often gone out of their way to "just say no," telling me to call CO instead (when I make it clear I'm not elite on CO) or even going so far as saying they're not supposed to give upgrades on CO. This always gets resolved in the end, but I don't enjoy making multiple calls (and holding) just to find a NW rep who knows how to fulfill the request.
I would suspect in my case, however, that this is due to the lack of a dedicated Silver Elite number at NW. In the old days when I had access to the Gold Line, this always went smoothly. I'm sorry to hear that even the great CO Elite CSR's can't make miracles happen. I'll be finding out soon enough now that I won't be using WorldPerks anymore...