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

  1. Open GCloud 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 GCloud 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, GCloud will use any available connection.