from memory i have not deliberately removed the i386 package, but you are right it is not there, however rpm does seem to know about /bin/tar
# rpm -ql tar /bin/gtar /bin/tar
<snip>
although i agree its something rpm db related as reinstalling tar via rpm rather than yum solves the problem, however i dont see how this situation has arisen.
rebuilding the rpmdb did not help - installing the i386 package using rpm 'fixed' it but its still very strange