Upvote:5
No, you do not need a boarding pass to take the bus from T2 to T1.
I called Munich airport to confirm this, and while they don't like it, it will be OK if your partner explains the situation to the Condor check-in staff.
However, given that you don't have a visa, you may well not be allowed to board a plane, since you have two separate bookings and the airline will consider Munich your final destination.
Contact Thai Airways and clear this up with them.