WiFi on my desktop computer and nighthawk extender

This is probably a dumb question but I'm going to ask it anyway so please be kind....  I have the Nighthawk X6 Extender hooked up in my office - I have it set up through the app.  My question is, when I use my desktop computer (MAC), should my wifi be set on my home wifi router connection or should I choose a wifi that is labeled Netgear - there are a few listed when I pull up the wifi connections? I'm not really sure that my desktop is making use of the wifi extender. 

Thank you

Janetapp2