I have received a confirmation from the hotel which shows the credit card details, however I have not seen the charge on my acct.

Within the confirmation email, I can click through to the hotels webpage where I can use my name and reservation number an also pull up the confirmation. From there I have even ‘modified’ the reservation by reentering my same credit card details, which are accepted (again) and then I receive another confirmation.

Since the booking is refundable until the day of arrival, my _guess_ is that the card is being taken as a guarantee and will be charged at the last cancellation time.