Clearly unconstitutional.
You'd have a hard time making that argument. General Welfare might not apply to local theaters and art shows, but a lot of the funding is for broadcasts, which reach pretty much everyone.
How is that relevant?
Quite so. Artwork is clearly and firmly in the realm of state power, and is therefore beyond the reach of the general welfare clause. The fact that it might affect people in different parts of the country is not the sole factor in determining if the general welfare clause's requirements have been met.