Welcome to Flyertalk and welcome to the BA forum Muzer, I hope your trip works out well and you have a good time.

I am sure the Bavarian contingent of this forum will be best placed to advise, but I know that usually that's an airbridge arrival, though few things in aviation are guaranteed. And that the taxi timing of 30 minutes seems about right to me and though I normally try not to use taxis, in this scenario I would be expecting to use one, and it has various advantages here, not least the taxi rank at the station is right by the door. And German trains are not always on time these days.