Yes, it does not matter which territory the troops on the transport are invading. The amphibious assault is in the sea zone adjacent to a territory with an airbase, which is all that is required.
Marsh
You seem to confuse the one-time bonus with the 30-IPC bonus, that is granted for the fulfillment of the respective National Objective (NO).
Of course the one-time bonus is granted only once - but the NO-bonus is granted round by round, as long as the NO is fulfilled.
They are based on different requirements.
@Panther Ok, thank you.
@Krieghund Thank you!