I used some root stimulator when this first happened but wasn't quite sure how often to use it.

I used some root stimulator when this first happened but wasn't quite sure how often to use it.
There are two possibilities ; one is that you actually have two different plants, which easily happens because tiny seedlings are difficult to separate, and it may not have been clear that two were being put into the same pot.
The other explanation is that unifoliate and bifoliate are not quite as clear cut and black and white as the words suggest. Often enough, a bifoliate will have some unifoliate growths, and vice versa.
If and when you get flowers on both kinds, you will be able to see whether you really do have two different plants.
In the meantime, rejoice, you may have had two for the price of one ! What's to grumble about ?

Thanks for the info., Dorsetman. Believe me I'm not complaining. I'm new to all this and was just a bit confused. I can't wait to see what develops because this plant came from my favorite grower. I'll keep you posted.