[curt.clifton]

If I set Projects to show Available actions, then I can confirm that a task in the same circumstances as your ABC company one does not show under Projects on the iPhone. That's a bug. The task does shows under Contexts and under appropriate perspectives. Switching to show Remaining tasks in Project mode and Available ones in Context mode causes everything to appear (or not) as expected everywhere.

Perspectives seem to ignore the "show" settings, using the view bar settings from the desktop instead.

Rather than eliminating your nested actions until there is a bug fix, would it be less disruptive to switch Projects to show Remaining? The remaining but not available actions will still be in gray.