To play the bounty hunter game and to see some of the animation with the statues you need a Play Disney account linked to each MB+
If anyone that you manage in MDE is over 18 and they want to be able to play the bounty hunter game or collect the statues they will need their own MDE and Play Disney app account.
My DD has a maingate pass and an AP. Her MDE and Play Disney app are linked to the MG and her AP is basically another person that she manages. She can’t use the MB+ that is linked to her AP because her Play app is linked to her MG.
We talked to GS and there is an update on the way.
Here is some info on creating play app accounts for under 18. I have not done this though so no first hand knowledge.
DD’s MB+ still lights up and vibrates at the statues but she can’t log into see the ones she has collected. I’ve also heard you can collect the bounties without the play app step but I have no idea how you would do that as it seems like a crucial and fun part of the game.