Yes, I can think of no reason why you shouldn't apply. Just contact NCL on the net or by 'phone or letter. It does take a little while to process. ..... Neil.
You are enrolled as a member from your first cruise ,you should get details through the post of any offers .if not contact ncl with your past cruise dates.
I went on NCL Jade in June and the atomatically sent me Lattitudes card about a month later. looks like a credit card.