We booked a trip with Grayline in October. We were collected at the hotel in the morning whereever we were going (about 8.30 I think but cant remember exactly) and taken to the central depot where we booked in then go on different coaches depending on where we were going.
It took about 60-90 mins to get there but the driver pointed out lots of places on route and gave useful tips about San Diego zoo and seaworld.
We then dropped people off at the zoo first then onto Sea world. The tickets to get in were included.
We were then collected 30 mins after the park closed (about 6.30) and taken back to Hojos (via a few other hotels). On the way back the driver put a movie on for us to watch to pass the time
It was definitely a good way to visit