I think that's a good and viable strategy! You're probably not going to have NPs in your earliest cities because that's where you're focussing your infrastructure. Bu tif you're going for a culture victory you could found or conquer more unspoilt cities later on to capitalise on the sweet tourism.
Assuming NP tiles have to be 'worked' to be any use - all but certain they will be - you would also have to do what it took to raise those cities up in population. And the city needs to be producing culture to claim the tiles, as another poster remarked. And though we don't know anything about border expansion mechanics (AFAIK) a rainforest hex 3 tiles away from the city centre may never come within the reach of a city founded in the late game without major effort.