ATLANTA — Married same-sex couples will get tax benefits equal to heterosexual couples through a retirement plan offered by the University System of Georgia, following a Monday vote by the system's governing board. Gay marriage remains a contentious issue in Georgia, where a lawsuit is challenging the voter-approved ban on same-sex marriage that was added to the state's constitution in 2004. Attempts to get full domestic partner benefits at the largest university system school, the University of Georgia in Athens, have stalled in recent years.