If your CCL past guest # is in their system and you log on to CCL website to book, there are sometimes "casino" fares that are pretty good. They only run for a month or so, so you have to catch them.
We try to remember to contact the Ocean Players Club a few weeks before our sailings to let them know our booking number and sailing info.
Depending on how much you spent in the casino on past sailings, they will give you medium level or higher level freebies.
It would be nice if there were perks on the sister lines. Perhaps there are perks and were not aware.