Workitem type
You can sync one Rally Portfolio-workitem type with the piplanning app. It will allow you only to sync the portfolio-type which is the lowest in hierarchy. 
In this example above (screenshot) it will allow you only to sync the type "Feature". The reason for this: Parents of team-level work-item types (user stories) can only have the lowest of the portfolio workitem types as a parent.
Parent / Child links
The only link which is currently synced is the link between team-level items (user stories) and the lowest portfolio-item (Feature).
Filtering
To prevent to have all workitems of a certain type on the program-backlog board, you can set a tag to specify which items you want to have on your piplanning backlog board. You can select one more tags. They will be combined as AND.
WSJF or Preliminary Estimate (Step estimate)
You can sync either the WSJF value or the a value from a Rally select-list (dropdown) to the field on the bottom right of the backlog sticky note.
