Driving to Yosemite

We are coming into Yosemite next month from I-80 (Winnemuca NV) we might go (1) thru Tahoe then on CA-88 coming in on the WEST side of Yosemite (Mariposa) or (2) go from I-80 to 95 to 359 to 120 then 140.thru the middle of Yosemite coming in on the east side head to Mariposa.
We have a 40 foot RV with tow...which is better? (is CA-88 ok?)

California State Route 88 is definitely doable in your coach. It is windy and will be sort of slow going. SR 49, if you choose to use that to get to Yosemite from SR 88 is even slower and has tighter curves. You might look at taking SR 88 to US 99 in Stockton and go south to Merced and then to Yosemite. If you are not afraid of some mountain driving take US 395 to SR 120 at Lee Vining and enter Yosemite that way. Yosemite valley can be very congested and with your coach it might not be that much fun.