You sure can. You can wait until you get your copy of the Crown and Anchor, or call RCi and request a copy. In the past they have honored the coupons even after you have booked the cruise. Just have your TA contact RCI and they will have your TA mail in the coupon for credit.
Thanks for posting the Coupon information from the Crown and Anchor. I hadn't recieved our copy as yet, and they have a good selection of cruises available. I have a couple that we are very interested in, and we get a little extra time to plan next years travel.