The game should transfer your content automatically if you sign with the same Apple ID on both devices. If you are having trouble with the sync function, try to follow these steps:
Before you start
- Keep in mind you can't transfer your content between different game versions (iPhone and HD)
- Make sure you have Game Center updated.
Check for an update via Settings > General > Software Update
- Check if you're connected to the same Game Center account on both devices.
- Remember that the iPhone and iPad (HD) are two different game versions, and the progress you make in one game won't be synced to the other.
Manual sync from one device to another
In the game you already have content, tap the icon in the bottom left to enable cloud save.
Next, activate the same game settings in the second device (the one that is blank).
Let us know the steps you've already taken!