He should be able to achieve this again, now that he's coaching a big club with a much better quality of players than he had at Leverkusen. The typical difficulty for a coach is not having quality players, making it very difficult for them to achieve success. But Xabi Alonso is at a team that has everything, and it should be much easier to achieve success, although the challenges are also much greater. I also believe Xabi Alonso will be successful at Real Madrid, but not in his first season because competing in the Champions League is different from competing in the domestic league.
It is quite possible that with higher level players Alonso will be able to achieve greater success. But there is a difference between Real and Bayer because when he was at Bayer no one demanded titles or anything like that from him. There was no such pressure on him, but at Real everything will be different. He will not have time to work with the team for long he will already need to win a trophy in his first season. And that could create certain pressure on Alonso, especially since he is still not a very experienced coach and has never worked with such big clubs.