Getting a secondary education masters degree can open doors that lead to more challenging educational or administrative positions in the subject area for which you are most passionate.
If your goal is to enter the administrative side of education, a secondary education graduate program that focuses on supervisory and administrative tasks in a school will be more beneficial and it will be to your advantage to pursue this specialization in your program. On the other hand, if you want to teach in secondary schools, then you will need to pursue a teaching specialization in your masters program.