Idine is the cashback program version of Rewards Network. Other Rewards network programs include Best Buy Reward Zone dining, Priority Club dining, Delta Skymiles dining, etc. When you eat at qualifying restaurants (search Idine to see), you get cashback/points from the program.

Idine happens to be tiered. After spending $750 a year, subsequent dining gets 15% cashback. I think you should stick with this program since the miles and points programs are significantly less generous.

For continuous spend, I do feel that Citi Forward is indeed the best card for eating out. However, at 75k TYP limit a year ($15k category spending), you will max that out in under 4 months. You may want a US Bank Cash+ card with one of the 5% categories set to dining. I do not think the Cash+ card caps their rewards.

redtop43 has a great list of cards with big signing bonuses. Study that list. Signing bonuses on those cards will help you earn a lot of miles fast. I will add to that list the ThankYou premier (if the 50k point bonus returns, since 50k points is worth $665 of airfare).