how can i add a new device in iTunes in iCloud->Manage devices??

Hi!

I have an iphone 5 with the software iOS 6.0.2 nd a Mac with the software OS X 10.8.2. The option of automatic downloads is enabled on both my devices but when i view my apple account it shows that my iphone hasnt been added to the list of devices in the iTunes in iCloud, hence any new app that i download on my Mac does not get downloaded on my iPhone automatically. I have to keep syncing my phone each time to get the new apps, please help me with this asap.

Thank You.