Yes, but when you dosed the tank the ammonium would start burning the fish gills right away, and while you are waiting for the bacteria to work, your fish are suffering. When your fish release ammonia, it is a more gradual release, allowing the bacteria to work. Seriously, unless you can find out what is in this product, DO NOT USE IT!!!. You do know what they have put in this product.
Edit: Actually, to answer your question directly, the plants will start using it as ammonia. The reason that people with planted tanks do not dose ammonia is because of the fish, not the plants. The plants would love it.