I boarded a gelding I had many years ago so was not the one who fed him. The barn manager and other boarders were always commenting on how they knew when I was coming before they could see me because although you couldn't see where cars parked, Sundance knew the sound of my car and would start whinnying and hanging over his stall door when he heard mine. No other cars then mine.
Horses in groups often pick out one or two they prefer to spend time with so if they can "bond" to other horses, the same can be said of bonding to certain people. Is it love or the same affection we feel? Maybe not, but having never BEEN a horse, I really can't say. Everything we as humans apply to animals, while based on "research/studies" is still speculation.