A new paper has just been published that explains the relationships and dependencies between the PeopleSoft Interaction Hub (formerly the PeopleSoft Applications Portal), and PeopleTools. This paper will help you understand which versions of the Hub work with which versions of Tools.
The paper contains information on how new customers can install the PeopleSoft Interaction Hub, and existing PeopleSoft Interaction Hub customers can apply PIH 9.1 Feature Pack 1 functionality if they are on an earlier version. It also describes how PeopleSoft Interaction Hub releases are aligned with PeopleTools releases, the general upgrade process within the Feature Pack model, and how customers can expect this to work with subsequent feature packs, maintenance packs, and bundles.
You can get the paper from Oracle support.