Alcoholism Support Group
Alcoholism is the continued consumption of alcoholic beverages, even when it is negatively affecting your health, work, relationships and life. If you think alcohol is causing you to lose control, it's time to seek help. Our group is a safe place to vent, check in, get back up if you fall, and reach sobriety.

There is not a lot to add to what cabledude has already stated, except that you could talk to your friend a bit more about this. If you know him quite well, why not ask him the questions you have asked here.
Many alcoholics that I know would not trust themselves around alcohol and some would definitely drink again if they were exposed to such temptation. I also know many alcoholics who are practicing a programme of recovery that has resulted in a complete change of thinking where alcohol is concerned and these people would be at ease in the company of people who drink.
The big question for you and your friend is this: Has he just quit drinking or has he made a start on dealing with the causes? If he is dealing with it, his visit should not be a problem. On the other hand, if he has just quit but has not taken other action, perhaps he should not be putting himself so close to temptation.
BTW, it is standard and healthy that he is not contacting you while he is in treatment. That is not a statement about your friendship -- it is part of his path to recovery.
When I quit, I was fine with others drinking, but during the first few months it was easier when I wasn't around it. Ask him. And even if he says that he is okay with wine around, keep it to a minimum.
And have some nice special fruit juices or sparkling water on hand that you can offer to him.