Google ist not the best info source for trains. Look at www.bahn.com. Type in your travel date and time. The Bayern ticket will be show up if you:
1. select "local transport only"
2. search for connections that start after 9am (on workdays, no restriction on weekends).
A Bayern ticket for 3 (usable on the Meridian train) will be €37 - much cheaper than sparpreis tickets for long distance trains. If you miss your connecting train in Munich you can take any S-Bahn (S1) as well.
BTW, the system will bring up some connections with trains going through Landshut, i.e. bypassing Munich. Avoid those if you want to do an intermediate stop in Munich.
Buy your Bayern Ticket on the spot (from any ÖBB or DB vending machine in Salzburg Hbf); pre-booking has no advantage and the tickets are non-refundable.