@aedifex Support for tags has been added in the latest WP Workbench 2.1.0 release.
To display it, enable the tags column in the module configuration. This adds a clickable row that allows setting tags separated by commas or semicolons, with filtering available either through the select dropdown in the top right or the standard table filter.
Note that the current version of Webmin and the Authentic theme does not display the select box neatly on the top right, and it appears on the top left instead. The next Webmin update will fix this as well.
@Joe, please push it to the other repo too.