You know I'm thinking we don't need a tag patterns feature.
I am going to create a directory with one dummy file for every media type (music, movie, TV, audiobook, book, etc.) and I am going to tag each of these files with the pattern I use for that media type. Then I am going to open that folder in Drives and Devices and leave it permanently open in a tab. When tagging a new file I will pop back to that tab, copy the appropriate file, go back to my tagging tab, and paste. Achieves the same thing as a tag patterns feature with no extra work for JRiver.
And I just checked, a copy one and paste to many works so we are good to go.