Okay, here, the rating of a cartel increases by playing wars (wining), gaining members in your cartel (as many medals they personally have, the more your cartel will get), also building and upgrading buildings at your Cartel Compound, as well as researching in the Capos Club.
By leveling up your Cartel level, you increase your points. And as you probably know, your Cartel level gets higher when you upgrade buildings and when you do researches.