Should be possible.
Caveat: Works ONLY if the primary phone/tablet can forward the stream data to a secondary PC/phone/tablet.
If running an
Tello EDU in AccessPoint mode (or however it is called when
Tello & phone both connect to an existing access point) this should be no problem.
If running in normal mode where
Tello is creating it's own Wifi then this won't work. While
Tello allows two phones to be connected to it's wifi it does not route network traffic from one phone to the other.
Workaround: add a suitable Wifi repeater as it will allow traffic between all connected devices