I am puzzled as to what you think is missing in the manual.

"Bytes and Byte Array Methods
Bytes and bytearray objects, being “strings of bytes”, have all methods
found on strings, with the exception of encode(), format() and
isidentifier(), which do not make sense with these types. ...
Note
The methods on bytes and bytearray objects don’t accept strings as their
arguments, just as the methods on strings don’t accept bytes as their
arguments. For example, 
"
I believe you are right that bytes => bytes/bytearray in the second help
entry.