Yes, it can. To activate this option, please:

  1. Open G Cloud App.
  2. Tap the Menu icon  in the upper left corner of the app.
  3. Open Settings.
  4. Tap the Automatic Backup option.
  5. Change the Connection Type to Any connection (3G/WiFi…).
  1. Open G Cloud App.
  2. Go to the menu in the upper left corner.
  3. Tap on Settings.
  4. Tap on Use Cellular Data.

 If at anytime you run the backup manually, G Cloud will use any available connection.