The File step for actions now includes an option to specify tags.
Additionally, the FileManager class for use in Drafts scripting (Action Script steps) now has getTags() and setTags() functions to allow you to work with file system tags.
The File step is probably the easiest to work with, allowing you to set a comma separated list of file system tags. You can also use Drafts template tags in that field and the [[tags]] will give you a comma separated list of all the Drafts tags associated with the draft, which is quite convenient to give you a 1-2-1 mapping.