[4] He made his professional debut for Bayern in the Bundesliga on 7 January 2022 against Borussia Mönchengladbach, coming on as a substitute in the 75th minute for Marc Roca.
[6] On 12 October 2022, at the age of 16 years and 293 days, Wanner became Bayern's youngest player in the Champions League, when he came on as a second-half substitute to Dayot Upamecano in a 4–2 away win against Viktoria Plzeň.
[11] Four days later, he scored his first goal in European competitions in a 3–2 victory over BK Häcken in the Conference League play-off round second leg.
[14] In November 2022, he was invited by Ralf Rangnick to watch and meet the senior Austria national team in hopes to join and represent them for the UEFA Euro 2024 in Germany.
[17] His father Klaus is a mechanical engineer and former footballer who played as a midfielder, he helped Austria Lustenau as its captain to promotion to second tier 2.