Hi gobananas,
Sorry this is kinda late

. I also suffer from emetophobia, and am especially worried about getting sick in public. I have been diagnosed by a psychologist and a psychiatrist as having a social anxiety disorder (but with some other anxieties mixed in there too). I don't have OCD, but my psychologist has made me realise that I do wash my hands more than the most people do (to avoid germs that might make me sick). This is something I need to mindful of, to avoid it escalating into OCD. So, in answer to your question, I would definitely say that emetophobia and OCD are related.
Also, SouthernBelle is right about the CBT. I have been undergoing CBT for about 6 months now, and while I am still very anxious and worry about getting sick, I think I am slowly improving.
P.S. If you haven't already seen this website, you might find it helpful:
http://www.emetophobia.org/default.asp