Can I bake bread with long-life milk?
Yes, you can definitely use UHT milk in bread. 

UHT is not usable for some applications, because its proteins have been changed by the heat. But in bread, you don't need the proteins from the milk. Bread recipes include milk to make the dough richer, so it is mostly the fat content that matters. Using UHT won't change anything in the dough structure. I even think that the usual unpleasant taste won't be noticeable, but I am not so sure about that. Still, it gets diluted a lot in dough, so if you can drink UHT as-is, you shouldn't have a problem with the bread taste.