First Amendment Establishmentarianism

Reading about a Jewish school's threatened lawsuit because of moot court competition was scheduled on the Sabbath clarified my thinking: any public accommodation specifically for religion violates the anti-establishment clause of the First Amendment because it requires governmental determination of what constitutes a "religion," as opposed to individual or group preferences based on moral, aesthetic, social, or historical grounds, thus "establishing" religion. Of course governmental action that targets a religious belief (e.g. deliberately scheduling a competition to disadvantage those who observe the sabbath) would violate the free practice and equal protection requirements of the Constitution.