You have been waiting long enough: just update your Team Explorer to Update 3 of the 2013 version and you will immediately get the support for Work Item Tags in TeamCompanion!
Work Item Tags are one of the never features in TFS which provides you the option to additionally categorize and filter your work items. Work items are easily tagged using the work item form in Team Web Access or in Visual Studio. Tags can then be used for filtering in project backlogs and work item query views.
After you update your Team Explorer to Update 3 of the 2013 version, you will immediately get the support for Work Item Tags in TeamCompanion. Tags are visible in the work item query result list and managed on the work item form.
Filtering on tags in TeamCompanion works differently than in Team Web Access.
The TeamCompanion’s full text search applies to work item tags as well, and is precise enough most of the time. If you explicitly want to filter on a tag, you just need to be a bit more specific and use the syntax of the advanced search using work item fields in format: [Tags]=value.
Tags are also available in the product and iteration backlogs.
We wish you happy tagging in TeamCompanion!