I have used the ST chip to switch ON/OFF several 250 W Sodium lamps throughout a public lighting network. No problem up to about 2 linear kilometers, except if the lamps use compensation capacitors. This capacitors decrease the signal level a lot.
A benefit of the ST chip is that it meets the Europen requirements for power line communications.

I couldn´t test the TDA chip because (some yeas ago) Philips had discontinued the production. I don't know the current state of this product.

Alfredo.