Hi Robert,
I'm not entirely sure I understand what you're asking, so please set me straight if I've got it wrong, but I think you want to have a UIView displayed above the AGSMapView and you want it active (i.e. the user can interact with it) only some of the time?
Take a look at this post. You could set the userInteractionEnabled property of the UIView displayed above the map to control whether it traps UI events or not. Set it to NO and the events pass right on through to the map.
Again, apologies if I've misunderstood. Let me know.
Cheers,
Nick.