I have the last version 2.0.1
If TTIWIPhoneList.Items is empty when rendering I can not add asynchronously new items.

As a workaround because my list is not in main region I have written into the TIWAppForm.OnRender:
And I asynchronously modify the list before the transition to the region with this list.

This is a known limitation of the TTIWIPhoneList.

I would recommend using the workaround which you are using now.