Bonding is accomplished during the early years. After that, it's too late. After his accident, my son and I were no longer bonded as we once were. I believe he accepts me as his mother even though he doesn't recognize me as his mother. I believe, also, he has learned to respect or even love me, but that's the cold truth of it.
Some days are harder than others.
Most of the time I'm able to push reality somewhere back in a hidden section of my memory. I don't have to be around first-hand knowledge of my son's amnesia on a day by day basis and am spared the anguish such as that experienced by his wife. Her love never faltered. She softened the facts for me in such a way that it would nearly always be much later when the full realization of the reality of it all would hit me smack in the face. My son literally started over from pre-school days.