That my JAA currency maintains my 'piggyback' licence currency without need for the FAA biennial, notwithstanding the fact I am in a US aircraft?
Correct, I think.
IO,
If we are talking 90 day currency for the carrage of passengers then yes, I agree; the JAA currency also counts as FAA currency. ie. it doesn't matter which licence you were relying on when making your three landings.
But the poster specifically mentioned the FAA Biennial, and as such we very much disagree. Every FAA licence holder must have a Biennial in the previous two years to fly. It doesn't matter whether the FAA licence is a standalone one, or the piggy back one based on a foreign licence....both need to do FAA Biennials. This is been confirmed to me by two different FSDO's, and a number of times during my study for the Flight Review, and if I remember correctly is mentioned on the documentation that comes with the piggy back licence.
dp