Whilst Webmin doesn't have phpMyAdmin as a native module, it does have the ability to view the tables and view and edit the data. Its not as nice as phpMyAdmin (or the MySql client-side GUI query browser tool - that's good). Of course, it does have the 3rd party module you can easily install.
the standard module is primarily there to manage MySql databases (eg securitry, permissions, config etc).
Install webmin yourself. Add Dag Wieer's repository, and "yum install webmin" easy and very much recommended by me.