This bug is still present in RHEL6 with MariaDB-server-galera 5.5.34 installed. It affects postfix as mentioned but also perl-DBD-MySQL so I can't install mytop because it depends on this package.
--> Finished Dependency Resolution
Error: Package: perl-DBD-MySQL-4.013-3.el6.x86_64 (rhel-6-server-rpms)
Requires: libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.47-4.el6.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.52-1.el6_0.1.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.61-1.el6_2.1.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.61-4.el6.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.66-1.el6_3.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.66-2.el6_3.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.67-1.el6_3.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.69-1.el6_4.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.71-1.el6.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
Available: mysql-libs-5.1.73-3.el6_5.x86_64 (rhel-6-server-rpms)
libmysqlclient.so.16()(64bit)
And installing MariaDB-compat does not help.
repoquery -ql on MariaDB-compat and mysql-libs leads me to think that maybe you should have both installed, but you can't because of this error.
Package mysql-libs-5.1.73-3.el6_5.x86_64 is obsoleted by MariaDB-shared-5.5.35-1.i386 which is already installed
Re: mysql-libs dependancy not met in CentOS/RHEL 6
Where's the spec file? mysql52-ourdelta-centos.spec isn't even in the official ourdelta repo.