Broadly speaking, you can double dip, triple dip even quadruple dip

The thing is, some restaurants sign up for multiple dining programs besides Idine such as:

Restaurant.com
Dinnerbroker/
Opentable
Thedish
Entertainment

Some of them give % off, some are coupon/Giftcert based, some have their own points.

If you leave in a major metropolitan area like NYC or SFO it easy enough to locate and combine multiple discounts; it is almost as fun as earning miles.