The main thing to keep in mind with this tour is a lot depends on the time of year you go. My wife and I went on this tour in April 2018 and as a result the road to Glacier Point was closed and the Mariposa Grove was closed for maintenance.
We got our Amtrak reservation and hotel information about two weeks before the trip. Being as there is no rail route between LA and Bakersfield that leg is on an Amtrak bus. The trip was scheduled so that we only had about 15 or so minutes until the train left which spared a lengthy layover in the train station. The return train was delayed due to track congestion but that's not a problem in that Amtrak buses will wait for you to arrive if your connecting train was late.
We were put up in the Radisson downtown which was a very nice hotel. For dinner, there is a great brewery/Mediterranean restaurant, PK HoP, which is located about two blocks south of the hotel on Van Ness.
We were instructed to arrive at 7:00 AM in the lobby but we were greeted by our driver who arrived 15 minutes early. Our driver drove us to Oakhurst where we met our guide. Due to a cancellation we managed to have the tour all to ourselves. Our guide was extremely informative and made multiple stops for great photo opportunities. We got sprayed by Bridalveil Fall, which was at almost maximum capacity due to flooding the weekend before, got a great view of El Capitan, and walked to the base of Yosemite Falls, while meeting a herd of deer on the way up. Our lunch was provided, which included an insulated tote bag that we got to take home with us. Our guide then took us to a meadow near El Capitan and took pictures of my wife and I with Half Dome perfectly situated. After that, we were given the option of touring the Wawona Hotel (which we declined since we were there for the natural part of the park) and we were taken back to the Fresno train station.
This trip was definitely the best way to see Yosemite from the LA area if you're not overly enthusiastic about camping or waiting six months to get a lodge reservation. It's well worth the money.