I booked a hotel through the UR portal over Christmas, after trying to book the same room via Priceline, but failing due to technical difficulties with the Priceline website. When I showed up at the hotel, the reservation paperwork I was given said something about it being booked through Priceline - so I was worried my Priceline booking had gone through somehow in addition to the Chase booking.
After calling up and speaking with the Chase travel people, it turns out they sometimes use Priceline to make bookings, so from the hotel's side of things it looked like a Priceline reservation. Presumably they may use other third party booking services as well.