There may be design requirements (vice limitations) in part 25 which specify that a transport aircraft must be able to bank to so many degrees bit I don't think there's any operational limits.
Applicable company limits would be found in the SOP, and might be type-specific, although 30* sounds typical. Anything more than that would bother the pax.
There's nothing inherently bad or limiting about bank angle...it's all about the resultant G-forces so the airframe limitations are the load factors. How far can you bank in a coordinated turn without exceeding load factor limitations? 60* bank is easily within the the 2.5 LF limit which is the minimum for part 25.