Hi,
I have built a Web Map in Portal for ArcGIS. It uses Services exposed by a Federated ArcGIS for Server 10.2 server. The security applied to Portal is the Portal Built-in Security (Token-Based).
The WebMap works just fine in the Portal for ArcGIS.com Viewer, works perfectly in both the Collector and ArcGIS app for Android (tested it in smartphones and tablets) but it does not work in the iOS Collector and ArcGIS app versions ...
I have tested with an iPhone 4 (iOS 6) and with an iPad 2 (iOS 7). The map opens the basemap and can't even zoom in to the extent defined in the Portal Web Map.
Cheers,
Jose