I have used the benefit, but have not yet completed my stay. While I did call them initially to provide dates, location, etc, they got back to me within 24 hours via email.
I noticed there was an email address listed on the pdf containing the list of hotel options and use this instead to communication with them.
They provide you various room types and rates for both prepaid and refundable. The charge appeared on my statement as being billed directly by the hotel which hopefully means that any elite benefits apply. I provided my loyalty number as part of the booking and the booking shows up on the hotel website as normal.
Currently still waiting for the statement credit to appear. For prepaid, it should show up a few weeks after booking, for fully refundable, it should show up after completing the stay.