I do not think that the government is imposing any kind of religiously held view on us, by recognizing and/or giving preferential treatment to married couples. I do not see the traditional, committed, man-woman, monogamous relationship as a religious phenomenon, though it is has obviously been encouraged by Judaism and Christianity. Partaking in a religious ceremony, vowing before God commitment to one another, and then fulfilling that sacred vow throughout their life together is a religious phenomenon. If government were to require that a religious ceremony be a criterion for eligibility for recognition as a married couple, then that would be an imposition of a religious view.
It is certainly noble that government has long encouraged stable families and social groups via marriage. However, the fact that the goal was noble does not give the policy merit in regard to whether it is a proper function of the government.
Post above directed to stitifier.