Marylyn. Before the upgrade there was Message on the phone. After the upgrade, only iMessage and even my phone number is checked as my primary number everything goes to the iCloud account which is on my iPad. My wife is deaf so it is the only way we communication when we are not at home. Apple drops the ball on the IOS 7. Unbelievable!!
On my iPad, with iMessage, I can be reached via three different contact methods - 2 e-mail addresses and one phone number. The iMessage account is linked to my phone so I can see on both devices...
However, you can turn off any of the contacts on the iPad so that messages are only received on the iPhone. And vice versa, you can make it so the iPhone doesn't get messages via a certain contact and so only the iPad sees them. Take a look at this photo:
If you press on any of the checked lines under "You can be reached by iMessage at", you can stop the iPad receiving an iMessage via that number/e-mail address.
My recommendation is to set up your iPad and your phone so that they don't share any of the same contact points. This way, if people want to iMessage you, they'll have to send to that specific contact, versus one of many.
Hope this helps.
Marilyn