To Yosemite Valley
Oakland airport to San Francisco:
I took BART (the San Francisco subway system) from the Oakland airport (take the AirBART bus to the station) to San Francisco and walked to my hotel in the Fisherman's Wharf area. BART also runs to the San Francisco Airport, but the Oakland flight was more convenient in my case.
San Francisco to Yosemite Valley:
I took Amtrak from Fisherman's Wharf in San Francisco (SFW) to the Yosemite Valley visitor center (YOV). The SFW stop was just a small sign near the Hard Rock Cafe where there was bus service to Emeryville, CA which is just north of Oakland. Most of the other passengers on the bus were backpackers bound for Yosemite. From Emeryville, the San Joaquin train goes to Merced, CA. The seating is located upstairs in the cars and is similar to the first class section of an airplane with two large well spaced seats to either side of the aisle. The ride was surprisingly smooth considering that these rails are also used for freight trains. The route the train followed was quite different than that of the freeway. Most of the views were of farm land, but the tracks also passed through some industrial areas. From Merced, the Amtrak ticket included a ride on the YARTS bus into Yosemite. The total travel time was about 6 hours from San Francisco to Yosemite Valley.
From Whitney Portal
I got a ride from the trailhead to Lone Pine with another hiker. This was the only segment of the trip where there was no public transportation available. From Lone Pine, I took the CREST bus to Reno, NV. Check their schedule as they do not have service every day of the week. To get to Reno from Lone Pine, you will need to transfer to another bus in Bishop, CA.