The EMP effects for a small nuclear explosion at ground level extend only about as far as the blast effects. This would be just as true in a city. The forest of metal in the city will serve to attenuate the EMP and reflect it back into ground zero just the same as the city environment tends to attenuate TV signals.
Speaking of which, it is the same case with eardrum damage. If you are close enough to have your eardrum ruptured, you will also have a house on top of you.
TV signals are many orders of magnitude lower in power than the emissions from even a small nuclear fireball. ANYTHING is transparent to electromagnetic radiation, given sufficient signal amplitude...
Basically, if the fireball touches it, it's going to reradiate. If it's touching something the fireball touches, it will reradiate.