Turns out there is another lounge in PTY that is accessible with the Priority Pass. I had a short layover in PTY on Saturday. Since my arrival gate was right near the PTY Copa Club I popped in there for a 'to-go' peanut pack, then headed over to the real lounge where they served chicken and rice.
It seems mildly embarrassing to CM that a Priority Pass lounge offers superior food to a CM's flagship lounge, but I guess if there were a business case to change things, they would.