Workers at a National City Starbucks voted Thursday night 21-3 to unionize. Workers at an Encinitas location voted 21-2 to unionize in May, and a Hillcrest location voted 15-2 in August. Starbucks said in a statement that the next step will be to begin bargaining over a contract with the National City workers. The National City unionization is part of a national effort that has led to nearly 400 stores unionizing over roughly two years. There are four other Starbucks locations in National City.