The Restaurant at Meadowood in St. Helena joins Thomas Keller’s celebrated Yountville dining room, The French Laundry, in the top tier of Bay Area restaurants, earning three stars from the prestigious Michelin Guide. The two Napa Valley dining destinations are the only restaurants receiving three stars in the Michelin Guide San Francisco, Bay Area & Wine Country 2011, which is hitting book store shelves and online lists Wednesday. “We’re thrilled,” said Christopher Kostow, chef at The Restaurant at Meadowood since February, 2008. “I’m as happy for my staff as I am myself. This is a great thing to share with other people.”