I was going to say the 2 oz doesn’t last long but then after reading @Ahhsomeguy’s post I realized you have a 200 gallon tub. Ours is 450 so we use more than 2x as much as you will use.
I’ve never used bromine, I only know the basic theory. You can use chlorine, MPS, or ozone to activate bromide ions into hypobromous acid. So to answer your question yes, you can certainly use liquid chlorine to shock a bromine tub. Alternatively you can do what I do and get a SWCG for your spa and run it as a chlorine spa. I use the Saltron Mini. It maintains the FC when we aren’t using the tub and then I manually add liquid chlorine after our (long) soaks to take care of the bather waste.