If the airline allows it, you can use Wi-Fi and Bluetooth while in Airplane Mode. You just need to turn them on separately.
Do any of the following
Open Control Center from the Home Screen
Tap the Wi-Fi icon or the Bluetooth icon
You can also go to Settings > Wi-Fi or Settings > Bluetooth
If you turn on Wi-Fi or Bluetooth while you're in Airplane Mode, they'll be on the next time you use Airplane Mode, unless you turn them off while in Airplane Mode.