Scobie,
I had found another post in the Bose forum that also mentioned the Soundtouch 20 wasn't fully DLNA compatible. I've checked the user manual, and there is nothing in it that mentions assigning media servers. When I look at the app on my iPhone, I see the Plex media server that is on my laptop. I've stopped Plex and restarted the app and the JRiver media server doesn't get picked up. I've seen where people have tried to use the Plex media server and have had problems; probably due to the DLNA compatibility issues.
The app is terrible. My music library resides on my WDMyCloudMirror NAS in a share with FLAC and ALAC subfolders. When setting up the NAS with the app I couldn't pick the NAS share for the music; only the NAS. I had to modify the Twonky media server on the NAS to get things setup properly. If I didn't have the Twonky media server on the NAS, I might not have been able to use the NAS. Looks like I'll have to use the app to play my music from this speaker. At least JRiver works fine with my Sonos Play 3 speaker.
Because of the DLNA compatibilty issue I'm not going to pursue this any further. Thanks for everyone's help with this issue.
Gary