Yes it would be nice to have this option on Mobile but highly unlikely that will ever happen.
Why highly unlikely? It can’t be that difficult to add to the app.
When the PCEA (Launcher) App was first introduced I believe it was possible for a short period of time to invite Mobile players to play in Multi Player Stroke Matches. Not sure why it was taken away or if there were problems playing cross platform.
WGT has said in the past that they were "working" on adding the multi player formats to Mobile but that was a long time ago. Recently, WGTNico has suggested that it's still being "worked" on but who knows when that will become a reality.