It is not law. It was a vote among the Texas Educational Board to allow an optional addition to the curriculum for elementary school students as a READING exercise as part of Language Arts.
The Texas Educational Board can’t make laws, they can adopt rules within the confines of the law, but they cannot make laws.
Regardless, the Bible is literature and they only approved its use for reading. Not “Bible lessons” and it’s not required either.
If it were, it would violate The Establishment Clause of the First Amendment.
I doubt any school board is going to implement this, even if they did, it’s not teaching religion, it’s teaching reading, but I doubt they will just due to the controversy.