If we miss our train as a result of a plane delay do we have to buy new tickets or can we just get on the next train. Our flight from Vancouver is scheduled to arrive in AMS at 1:15 with our train for Paris leaving at 4:42 which should give us plenty of time but today I see the flight was delayed 1.5 hours which could cause us to miss our train. I just want to be aware of our options.
Depends on what type of Thalys ticket you purchased. If it was a discounted fare that is non-refundable/changeable and you miss your train you will not be able to simply "hop" the next train, you must have reservations. In this scenario you would have to buy all new tickets. If you have changeable tickets head over to the ticket counter and exchange them assuming their are seats left. Thalys trains typically sellout, but they do allow stand-by passengers in case there are no-shows.
If you really mean Rail Europe, then go to the schedule and click "details" under the "Economy restricted" fare. I did that for one connection, and it said the tickets were "non-refundable, non-exchangeable". I think that means that you lose that "low-fare" ticket and have to buy a whole new one. But a lot of tickets from Rail Europe are that way, even the unrestricted ones.
If you wanted to go to Paris, you should have booked to Paris, not Amsterdam.
I usually suggest that people who are flying in on a trans-Atlantic flight should plan at least a day of sightseeing in that city before trying to use the highly discounted, non-exchangeable, non-refundable fares to somewhere else.