In order to get the music that is on your iPhone onto your iPod, you must sync your iPhone to iTunes on your computer and then sync the music to your iPod from iTunes. There's no way to transfer music straight from the iPhone to the iPod.
In order to make sure that everything transfers to your iPod, be sure to transfer purchases from your iPhone to your computer first by going to File - Devices - Transfer Purchases in iTunes. Then connect your iPod to your computer and click the icon with your iPad on it. Then you should click the Music tab across the top and select the music that you want to sync to your iPod and click the Apply and Sync buttons in the bottom right corner of iTunes
To transfer photos, music, contacts and apps from one iPhone to iPad:
1. Connect two device to PC.
2. Choose the category list of iPhone that you need to export files
3. Check the files that need to export in the Content Panel and click "Transfer file(s) from device to device" button
4. All the checked files from your iPhone can be transferred to iPad.
And there are two articles about transferring files from iPhone to iPad: