The full-back appeared in the second half of the Euro 2016 qualification clash, scoring his side's fourth to round off an emphatic performance from the European champions.
"It's a dream debut for me. I'm very happy with my debut for the senior team and for my goal," he told AS.
"I felt very comfortable in this group thanks to Paco Alcacer. There are a lot of new, young players who can do well and help the team, as we're seeing. David De Gea is a goalkeeper at a great level."
Bernat joined Bayern from Valencia this summer.