The partner bonus and the gold challenge are completely seperate, and if offered, they would be under seperate cover. If you already have Gold, I think it unlikely that you will be offered the challenge.
It seems to me that I was offered the challenge after being at the Club level for awhile, and then significantly reducing my travel for a several months. (For no other reason than we had lots of work in my home city, and therefore I had no need to travel.) It appeared the offer was to entice me to travel with CP again, as I suspect they thought that I had jumped ship.
Bear in mind that all these offers, upgrades, incentives, benefits, whatever, are not given out cause the airline is nice and likes you. Rather, they expect to see some "return on investment" for each dollar they spend on their frequent flyers. My guess is they would only offer the challenge to people they feel will travel with CP because of the offer, when otherwise they might not. See if you can figure out how that might apply to you. Perhaps you can briefly change your flying patterns to become "targeted."
But we're into the realm of speculation here, so your mileage may vary.
Regards,
Ken Hamer