As of bug 409883, emerge-webrsync is installed into bin, not sbin. I checked 2.2.01.20366 and the patches are present in the Makefile but it still installs into sbin. I don't know where else to look, can you check this out?
Most likely you checked the wrong Makefile. The Prefix branch uses the autoconf-based Makefile(.in)s. ;)
Ah, yes. usr_sbinprogs = \ ... emerge-webrsync \ ...
http://prefix.gentooexperimental.org:8000/portage-prefix/rev/093338796ad7
released in 2.2.01.20389