How do I transfer my music using iCloud from my iPad to my iPhone5

Welcome to the Apple Community.

You can re-download content purchased from the iTunes store (availability varies depending on location) using the purchased option which is revealed in the iTunes app on your iOS device by tapping the more button at the bottom of the screen.

You can download music purchased from the iTunes store as explained here: http://support.apple.com/kb/ht2519. If you want to use iCloud to download music that was not purchased from the iTiunes store from iCloud, you will have to subscribe to iTunes Match on your computer. (http://www.apple.com/itunes/itunes-match/)