On what grounds do you think Bannon can get his conviction reversed on appeal? I'm betting you were not (and still are not) aware of a single ground that Bannon plans to set forth on appeal when you typed that there is a high probability that "Bannon wins his appeal."
There is almost zero possibility that Bannon gets any kind of reversal on appeal. This was an easy contempt case -- he was duly served a subpoena and publicly defied it. He made whatever factual and legal arguments could excuse that. Then he was convicted by a jury.
What grounds do you believe Bannon will be able to reverse, in whole or in part, his conviction by a jury on contempt counts? You don't have any in mind, do you?