Why is blockchain.info allowed to have an iOS app but coinbase is not? I saw that Coinbase's new wallet app has been pulled from the iOS app store.

Is there anything about the Coinbase wallet app that was different from the blockchain.info wallet app?
Probably because blockchain.info is just a wallet whereas coinbase actually allows you to buy and sell bitcoins. Exchanging one currency for another (where one is only loosely labeled a currency by the government) is where you get into sketchy regulatory waters. I imagine these are the types of problems apple would like to avoid.