Seems to me that, like just about everything about pitching, command can be honed and improved with good coaching and practice, but I don't think it can really be taught. Think about how many pitchers you have seen over the years with good (or even great) stuff, but poor command--or who can't even consistently throw strikes. MLB teams have hundreds of millions of dollars in incentives to figure out a way to teach command. In the current era of super slow motion video and computer-aided analysis, I expect coaching techniques will improve. But at bottom, I think you either got it or you ain't got it...