Does Airplay function require host Hackintosh has an installed and driven wifi card or USB dongle?(I have ipad Air 2), as a prerequisite? thanks
No not at all.
My 1 gig. ethernet network backbone is flat, with all my iMacs and NAS's running exclusively on ethernet with WiFi not configured on these network devices at all. ( Yes, I consider my iMacs to be network devices as well.) Even my Apple TV 4's are only connected or rather only configured for ethernet.
My Network also comprises of a number of "unmanaged" ethernet switches. Three of these switches are dual configured for ethernet as well as WiFi - in the 5 gig frequency spectrum as 2.4 gig is too interference prone. These dual configured switches are strategically placed throughout my residence in order to ensure that my iOS devices will receive a strong WiFi signal wherever I want to use any of these devices in my fairly spread out environment.
How does airplay now work ?
From the iMacs exclusively via ethernet to any one of my 2 Apple TV 4 boxes and 1 apple TV 3 box, on my network.
From any one of my iOS devices via WiFi to the nearest dual configured switch, providing the strongest WiFi signal. From there the signal continues via ethernet to the respective apple TV that should receive the airplay stream as originally designated by the iOS device.
Even handoff between my iOS devices and my iMacs work with this kind of setup.
One can also consider the three dual configured switches as locally functioning hotspots although one of these switches is also configured to function as an ADSL access point to the internet via my service provider.
Enjoy.
Sorry
@toleda that I chipped in, but I thought I could assist in this instance as my scenario matches exactly what
@susudio enquired about, or so I believe