Flixbus
 http://www.flixbus.com
Select as Destination “Bolzano”

Südtirol Alto Adige Bus (Dolomites Airport Shuttle)
 http://www.altoadigebus.com/  
 Select as Destination “Bolzano Stazione die Treni Area Taxi”

Train
 http://www.bahn.de
 Select as Destination “Bozen / Bolzano”

If you are travelling by air you might also consider to book your flight to  Verona instead of Munich.  By train, Verona is only 1.5-2 hours far from Bozen.

With these alternative travel options you arrive at Bozen, about 15 kilometers away from Tiers.
To get from Bozen to Tiers, you have two options:
By taxi
The taxi stand is situated at the  Central Station of Bozen.
Taxi Phone: +39 0471 98 11 11  
Approximate costs (Bozen-Tiers) € 60,-

By the public bus
Here  you can find the timetable for February/March 2018.