Q: iTunes didn't see iPhone on Wifi

Just in case check this

Set iTunes to sync your iOS device over Wi-Fi

1. Open iTunes. Make sure that you have the latest version.
2. Use the USB cable that came with your iOS device to connect it to your computer.
3. In iTunes, find and then click your iOS device.
4. On the Summary tab, select "Sync with this [device] over Wi-Fi."
5. Click Apply, then disconnect the USB cable.
6. Choose which items you want to sync, then click sync.

When the computer and the iOS device are on the same Wi-Fi network, the iOS device appears in iTunes. The iOS device syncs automatically whenever it charges and iTunes is open on the computer. Learn more about what you can sync and how to sync specific items.

From Sync your iPhone, iPad, or iPod touch with iTunes using Wi-Fi - Apple Support