Are you talking about linking to your reservation number? If so, it doesn't matter, you will be asked and/or tell your server you are using the DP before you order.
If it is something you have to pre-pay (like one of the dining shows), then yes, you will want to get it linked otherwise your credit card will be charged the full amount when you book it. I made that mistake when I booked the BBQ and when I called the dining line, it was an easy fix for them to refund me and then add my DP to the ADR. She also told me that I could either do it on the phone right away or, they could do it at the location as well.