I was under the impression that you used sino if there was no conjugated verb after using sino in the sentence and sino que if there was a conjugated verb after using sino que.
In lesson 13.3 there is this sentence: Mauricio no solo es director de ventas, sino tambien es programador.
There is a conjugated verb after sino in the sentence so I thought you would have to use sino que.
Thanks,
Donnie Rea