I'm happy to say with a bit of fiddling around I have now successfully got an iOS 2D touch screen - object moves to target working.
If you have seen the Mouse Pick video, I followed that but here are some tips. Instead of Mouse Down, use TouchEvent in the input manager (see video). But a couple of things, you have to have an object for the mouse pick to 'see' in the world, or it doesn't pick anything, obvious really, so I set up a plane below my objects which filled my touch screen area. Setting the render mesh off doesn't stop the mouse pick working, but it stops the plane interfering with your design plans.
Hope that helps someone get there quicker. Thanks for the input Alex, being very new to PlayMaker, it got me working in the right direction.