Description of problem: I was pretty surprised to find that installing rpmdevtools didn't install the rpm-build package for me. It seems like rpm-build should be part of rpmdevtools.
$ rpm -qR rpmdevtools | grep build rpm-build >= 4.4.2.1 I don't know why rpm-build did not get installed for you, but as far as I can remember, there has never been a rpmdevtools release without that dependency.