There is a simple—but not particularly intuitive—solution to this. To summarize the issue: Without getting into details I don't fully understand, "Connected Media" is clearly something different than other views. It has special properties supporting online media, but one of it's differences is it's not available in Theatre View. Regular views, however, will handle any type of media—including those located on the Internet. So...
Create a "Radio" view with a Rule for file display that includes only online sources: ([Filename (path)]=[http:". Then drag & drop items you've added to "Connected Media" to "Radio" to "import" them. They remain the same "file" and can be tagged in either location, but you will be able to configure "Radio" just like any other view. Mine is a Panes view which allows me to quickly select a stream based on provider, genre, location, bitrate, etc. In the same way, a "Radio" view can be added to Theatre View.