Unfortunately belonging to CLIA is not as much of value indicator as people think.
CLIA is an industry organization that basically acts as a training ground and public relations arm for industry.
There really is no governing body on agents other than "the law of the land" (government).
I don't see an advantage in finding a local agent. For 11 years all my cruises have been booked with Internet based agencies (who could also be brick and mortar offices local to their area)
The key is finding a good one who is easily accessible via email and phone calls, and is helpful, and service oriented.