Bavarian regional pass

Yes, the Bayern-Ticket includes Salzburg.

I assume you do actually mean the Bayern-Ticket. The Regio-Ticket-Bayern is something entirely different. It is a ticket offer for a round trip, up to 50 km out and 50 km back, for €10.

The actual Bayern-Ticket (make sure you get the name right, because there is also a button on the ticket automats for "Regio-Ticket Bayern"), an all-day pass for all the regional trains in Bavaria, is also valid to some border stations, Salzburg, Kufstein, and Ulm, as well as on the Ausserfernbahn, the section of track thru the Tirol between Kempten and Garmisch-Partenkirchen, and for Memmingen to Hergatz via Kißlegg.

THANKS LEE FOR THAT ADDITIONAL INFO ABOUT THE ROUND TRIP TICKET. IT WILL BE USEFUL. SUZANNE

Lee, Thanks for the distinction. Once again I've learned something from you!