He's still getting drift and 'revs', though (from what it seems and from what the players and commentators have been saying).
Often when spinners bowl quicker they just bowl flat and straight which tends to make them less dangerous - Moeen's increase of a few mph seems to have made him more dangerous and less easy to just push around for a single. As I said before, I wonder whether some of that has come from Ajmaal (or at least from him watching Ajmaal).
Of course, it helps if you're bowling with a few hundred lead on the board but I don't think we should underestimate his performance on the last day of the So'ton test as there was a fair bit of pressure on him.
Maybe some from Ajmal but mainly from Bell who he has practiced a lot with and told him he needed to bowl quicker in test cricket than county cricket. Knows him well from his Warwickshire days as well.