Add Node Taxonomy to attached Files (enities)

I have a node with a file field of images. I am using media and I have a taxonomy filed "category" for the Node and the same taxonomy field for the File. I would like to create a node with attached files and select a "category" taxonomy for the node. Once the node is saved I would trigger rules to add that "category" term to all the files (entities) uploaded with that node. I cannot seem to get an action to add terms to an entity with fields.
Does any one know how to do this with entities? Any help is much appreciated!