You can make dining reservations 180 days before your arrival day for the length of the resort reservation. Because you have two resort reservations you will have to make them on two different mornings, 180 days before check in day for each resort. The 180 day for YC will be next Friday. Here's an online calculator:
http://pscalculator.net/pscalc.php
Online: 6 AM Eastern Time
Phone: 7 AM Eastern Time
Yes, you used to be able to book the dining reservations for a split stay at the start of the first resort res, but not any more.Thank you. Last year we had 2 hotel reservations and I made them all at once. Wonder if that changed?