The criteria for OMNI are typically 180 posts and 180 days but Randy Petersen has stated that entry is not automatic after 180 days. Apparently they scan your posts and ensure that you are contributing to the overall FT community and here for the points and miles. Once that happens, OMNI access magically appears.

As for the relation between CC and OMNI, the only one is they are restricted forums for new members. You have to contribute to the overall BB before access is granted. I am not sure, but I think SPAM also has some access limitations.

Welcome to Flyertalk - it is a fun, but addictive space.

Cheers.