Sorry, I didn't realize I got into a Carnival discussion. I'm pretty new to cruise critic and I thought everything I was following was Princess. I've only done couple short carnival cruises so I wouldn't know much about their process.
Members are eligible for a higher tier level on the next cruise following completion of necessary cruises and/or cruise days. Land portion of cruisetour does not apply. Only cruises taken on Princess® and P&O Australia count toward the Princess Captain’s Circle Program. P&O UK cruises are no longer eligible.
Above is from the Princess web site