In my experience, flights I've booked through united.com have shown up on my credit card statement as originating in Rosemont IL.
A flight I booked over the phone as a non-elite gave me a charge originating in "Pune, Maharas IL". I did not know the State of Illinois had annexed part of India. :-)
I have not yet booked a flight over the phone as an elite, but I would not be surprised to find Honolulu or Rapid City show up on my statement.