Let's see. I got Adams only, because there are enough wild ones around
I did not need a second for pollination. Although it is listed by EL as
good for shade, in the shade (I was hoping it would grow above the
house shadow eventually, so as to get a white bloom show in front of
the house in June) it did poorly. I took 3 cuttings/suckers from it
before it died, and those cuttings are now growing vigorously in a
place with poor, well drained soil that gets sun from sunrise until
1pm. I gave it no special care.

No berries yet. They are probably fairly strong, undemanding plants so
long as they get decent sun. They seem happy with clay or sand,moist or
well drained. I have another elderberry behind the garage, a full grown
15 ft bush, and my guess is that you need several plants to get wine.
You can buy several, or buy two (one for pollination) and keep
propagating the suckers as they appear. It is going to take a few years
for you to get enough berries.