No, he doesn't get his bottom up yet. He mostly pulls himself along with his hands, pushing down with one leg and crossing his ankles
I do try to crawl with him and he spends time with his cousin who crawls 'properly' on hands and knees but he doesn't seem interested in trying any other way at the moment. He has only been mobile for a couple of weeks, so hopefully he'll get the idea soon enough.
I know how important it is for babies to crawl, which is why I came up with this idea of encouraging him, since he just doesn't move very much if left on his own. It also lets me schedule in reading time which otherwise gets forgotten with all the million and one things I have to do in a day