I don't think you read the article because it clearly states that the restaurants they are talking about are in San Francisco where the wage is $15/hr + medical

I don't think you read the article because it clearly states that the restaurants they are talking about are in San Francisco where the wage is $15/hr + medical benefits. When you factor in the required medical benefits that could end up be closer to $20/hr which is much higher than the $5.50 you are quoting.