together= with each other
Now, we got the structure "to talk with somebody":
I talked with him.
He talked with me.
We talked with each other.
We talked together.
However, sometimes, we don't need "with" as in "date somebody".
I dated her.
She dated me.
We dated with each other.---> this violates the structure "date somebody" without "with"
We dated together. = We dated with each other.----> this violates the structure "date somebody"
We dated each other.---> this seems ok, but I am not sure.
I don't know whether the "with" in "talk with" is the same as the "with" in "with together".