This controller is compatible with PC and Xbox. It includes the dongle for PC.
Microsoft sells two products that include an Xbox wireless controller:
http://www.xbox.com/en-AU/Xbox360/Accessories/Controllers/xb…
http://www.microsoft.com/hardware/en-us/p/xbox-360-wireless-…
Fortunately, the controllers in each product are identical but one contains a PC dongle.
EDIT: Microsoft's customer service told me over the phone that this item and retailer qualifies for the cashback offer. Unfortunately, their customer service team made a mistake because Mighty Ape is not an Australian retailer so cashback is not available for this item.
From the cashback's terms and conditions:
MightyApe is a New Zealand based retailer. Are you sure they qualify?