I agree with you. Bayern Munich are still favorites to win the title. It is true that Leverkusen are still performing very well. The Leverkusen team has not yet faced defeat in any match. However, I have considerable doubts whether the Leverkusen team can maintain such a consistent performance until the end of the season. But Xabi Alonso is very hardworking. At the same time Leverkusen team is not dependent on any specific player. So the team is able to consistently perform well. Every player in the team tries their best from their position to perform well.
Bayern Munich are classically the favorite team to win the Bundesliga title but we all saw how much they suffered last season. The title was confirmed for Bayern Munich in the last game and after Dortmund ruined their record, they were almost the champion!
This season, Bayer Leverkusen took the place of Dortmund last year and they are even better right now. I think they could claim the first place until they will face Bayern Munich and at that time we will have a better look about the winner this season. It will be interesting to see another team getting this title after all
What Xabi Alonso and his team have been doing in the Bundesliga is very extraordinary and unimaginable. He has beaten multiple records in the Bundesliga by being unbeaten for so long. But I would agree with @Iranus. Bayern Munich are still the favorites to win this title. There will be a time when Bayer Leverkusen will drop points Bayern Munich will get some points to get ahead of them. But I think the match that will have the most impact on this championship title race is the match between Bayern Munich and Bayer Leverkusen. Whoever wins this match will get a good advantage, even if it is 1 point. I mean 1 point is a lot considering how the current race is going. Bayern Munich knows how to gain back their lead I believe.