Hi Jo, I must admitt I've read your post a couple of times and been reluctant to say anything, most likely because your situation is so foreign to me. I must say things look good for you right now. Why do you think it bothers you that no-one knows the two of you are seeing each other? Do you feel that his not sharing the information about your Relationship is a reflection of his lack of commitment? Just a guess here. Its great your going out, sharing some quality time.
My opinion about telling folks your together, is that its really more your business than theirs. You sound hesitent about even setting a date, so dont think about it for awhile enjoy the dating, you'll know when the time is right, heck maybe he'll let the world know. Keep in mind my advice maybe lousy, hopefully it will give you something to think about.
Remember time is on your side, so take it slow. Take care.