First, the superb Black Bass tartare is still on the menu. I just returned from lunch at Le Bernardin and had the dish: Wonderful.
Excellent - do you recall the amount of the supplement?
The supplemental charge is usually in the 20$ range. I eat at Le Bernardin quite frequently for lunch and often have a extra savory dish.
I also agree that you shouldn't miss desert. The pastry chef is one of the two best in the city. Only Sandro at Adour is as good.