Don't know about entagled communications, but f.e. Gunter Nimtz experimetns show that FTL communication is definitely possible. Tunneling through 1m gap is not very exciting, but nothing prevent tunnelling for much longer distances.

Also, long-range communications could be highly directed to save energy. You need much more energy to radiate in all directions, and the signal strength will fall proportionally to the square of distnace. Directed communications are free from that problem. If you create some kind of channel (wormhole, tunnel, whatever) to destination you don't have to radiate to all universe. So, even if civilisations of universe use electromagnetic waves, the probability that Earth will somehow cross that channel is near zero. Especially if it is some unconventional channel, out of our spacetime.

Another option is use scaled down subspace for communications. In such subspace distances between objects much lower than in our space, say, light year is an inch. There will be no problems to use electromagnetic waves for interstellar communications, but humans have no technology to access such subspace. Also, there could be infinite number of possible subspaces, so, apart a technology, you have to know which subspace to listen.

In any case, there is nothing unusual that SETI project gave no results.