Is your Jeff's iPhone personal hotspot enabled on your iPhone?
The screenshot you provided is a list of available WiFi networks; if Jeff's iPhone network is not showing as available then it would appear that your hotspot is either not working or its signal is too weak to be detected.
After checking your iPhone settings, I'd suggest shutting down & restarting both your iPhone and your Mac. See if it reappears; if not, then we can pursue other avenues.
And just for information, if both your iPhone and Mac are already on the same WiFi network (as you said in your original post), why do you want to use a hotspot instead?