You can go Sikkim and Darjeeling. February is the best time to visit the place. In Sikkim you can cover Gangtok, lachung and lachen.
I'm sure you will enjoy the place.
Visit my profile for Darjeeling details.
If money is no Barrier then perhaps Rome or Paris is one of the most romantic destinations in the world for honeymoon couples. But you'll hv to apply for Visa in advance. You can go to Prague as well. it's a beautiful place and has Visa on arrival.