After about 30 minutes of perusal (admittedly, not exhaustive), the majority of ACs affecting transport category aircraft seem to pertain to certification. A search for "bank angle" was unproductive, but I did find the term buried in the text of at least one AC, so using the online search feature seems to have a limitation of some sort...title only, perhaps?

ACs regarding 121 operations were even less fruitful.

Did you have something specific in mind, or just the helpful prod that I took it as?

TIA