My experience at NY Penn: My taxi dropped my 3 pieces of luggage and me off at the side of the station with only an escalator and stairs to the station below. How am I going to get this stuff and me--safely--down to where I needed to go? An Amtrak employee was coming up the escalator and I asked her for help. She said that she was on her lunch break, but she helped me get to the station where the Lounge and luggage check-in was close-by. I didn't have the presence of mind at the time to offer a gratuity and I have felt badly for some time because of my failure to do so. Other Amtrak employees at NYP whom I encountered were also pleasant and helpful.
Well, don't feel bad. It was her choice to help you and having been in the airline industry in a past life, I can tell you that sometimes, in the world of transporting passengers, helping someone out when you're on a break is its own reward.
Edit: it's never too late to call customer service and give a compliment.