The LG G4 has root on most US carriers. If you're on Marshmallow then just downgrade to lollipop and root. Then you can get hotspot. Or am I missing something?
http://xdaforums.com/att-g4/help/root-downgrade-options-h81020n-t3360743
After reading a bit on this topic. It looks light the LG G4 AT&T software version I have won't let us, in the United States.