Small business ins question

I work for an electrical contracting company that is a union based company. I am not one of the union employees, so do not receive any of the union benefits. My girlfriend also works for the same company and is non union also. She receives healthcare benefits paid for by the company. she also works in the administrative department. I do not work in that department, and am not eligible to receive any healthcare plans paid partly or wholly by the employer. I am curious to know if they can pick and choose who will receive healthcare coverage benefits. I put in 40 hour workweeks just like everyone else in the company. The company has less than 50 employees.