the conventional definition of net neutrality is with respect to internet service providers favoring certain traffic over others.

you're correct that taxation of internet streaming content by the government is not what is conventionally meant by net neutrality.

however, I do think that taxation is highly relevant for issues of economic fairness. is Pennsylvania subjecting streaming services to a different level of taxation is their non-streaming competitors? that would be economically unfair in a similar way that non-neutral network access would be unfair.