Which ski pass, between IKON pass and Epic pass, should I buy if I live in the Bay area and mostly go to the Lake Tahoe area for skiing.

Although both passes provide great value when you visit the snow resorts more than 7 days each snow season, they have some differences that you need to consider before you make the purchase.
For IKON pass, you can access 14 ski resorts for unlimited time and over 40 ski resorts for max 7 days each snow season. The nearest ski resort for you resides in the greater bay area would be Palisades Tahoe. 
For Epic pass, the nearest ski resort near the bay area would be the North Star ski resort, Kirkland ski resort and Heavenly ski resort, all of them reside in the Lake Tahoe area. 
I would recommend buying the epic pass because you will have more options to choose from in the lake tahoe area.