Here is a Q&A from the Rewards page on Chase's website:
Q. What types of merchants are in the Theme park category?
A. Theme park category
Merchants in the Theme park category include amusement parks, carnivals, circuses, and aquariums. Please note that some merchants that sell goods and services within a theme park, such as food and drink, may not be included in this category
Sounds like restaurants inside DL are probably not classified as "Theme Parks". In fact, now that I remember, during last visit to DL in 2011 this card was offering 5% back on restaurants, and I did earn 5% for all the restaurants inside Disneyland that I used the card in.