1. Whenever the computer and the iPhone are on the same network, the iPhone will appear in iTunes, and you can sync it. The iPhone will sync automatically when Wi-FI sync is enabled, iTunes is open, and the iPhone is plugged into a power source and connect to the same Wi-Fi network as the computer.
   
2. Open iTunes.
   
3. To set up Wi-Fi syncing, connect your iPhone to your computer with the included USB cable. Click the device button in the upper right corner.
   Note: If you are viewing the iTunes Store, click the Library button in the upper right corner. The device button will then be visible.
   
4. In the Summary tab, select "Sync with this iPhone over Wi-Fi".
   
5. While the iPhone appears in the upper right corner of iTunes, you can select the content tabs and configure sync options.
   
6. Click Apply or Sync to sync the iPhone.
   
7. For more information, please visit Apple support articles: Syncing your data with iTunes using USB or Troubleshooting iTunes Wi-Fi Syncing.