The Bundesliga already belongs to them, I also think that the Bundeliga is a competition for Bayern Munich.
Union Berlin is expected to break Bayern Munich's dominance when they were top of the standings a few weeks ago. But what is happening now is that they have slumped and been thrown far from the position they occupied at the start of the season. Bayern Munich not only dominates the league, but the statistics they create will be very difficult for other teams to catch up with. It's boring to watch this kind of competition, but this won't change until there's a team that can actually beat them.
In current season we have no team which is capable of breaking dominance of Bayern Munich because they are superior in all aspects and things are looking much better for them even they were no good in early rounds of this season and Union Berlin done amazing job specially as they were dominating mostly peoples were feeling they will break things for this season but now suddenly they are also back into their regular position with their performance is also on decline.
And they are currently at fifth position with most chances they will drop because few teams are doing good job, and they have better chance for improvement after the break and going high into rank which is good but if Union Berlin also wants to stay at the top they have to improve performance and bring few quality players for the next round of this season.