I completely agree that this is a documentation issue.

Also, or perhaps for foolish completeness, in

http://docs.python.org/3.0/library/stdtypes.html

we would point out that the following group of string methods also work
for bytes and bytearrays.  Of these, only str type has format method.

"String Methods

String objects support the methods listed below. Note that none of these
methods take keyword arguments.

In addition, Python’s strings support the sequence type methods
described in the Sequence Types — str, bytes, bytearray, list, tuple,
range section. To output formatted strings, see the String Formatting
section. Also, see the re module for string functions based on regular
expressions."