Catalonian rhymes with:
macedonian, banyan, bennion, binion, branyon, bunyan, californian, canion, canyon, communion, companion, disunion, dominion, gagnon, grunion, henion, kenyan, kenyen, kenyon, kinion, kinyon, lanyon, macedonian, mannion, minion, munyan, munyon, nonunion, o'banion, obanion, onion, opinion, pinion, pinyan, reunion, runion, runnion, runyan, runyon, soviet-union, union, virginian
Catalonian sounds like:
caitlin, castellana, castellani, castellano, castellon, castillon, castleman, catalan, catalano, catalina, catalonia, cathleen, catlin, cattlemen, chitlin, coastline, codlin