No, government funding of charter schools, even if presenting religious views, is protected by the First amendment. Opponents wrongly claim, funding is tantamount to "establishing" religion, a violation of the First Amendment. But as long as parents have a choice to either send their kids to the religious school or to another "government funded non religious or other religious school" then the government is not "establishing" a religion the governed must embrace.
In fact, the opposite is true. If the government only funds non-religious schools, it is in fact establishing a atheistic religion. The only Constitutional way to fund public education is to provide school choice, thus not hindering the practice of religion. On fine day, SCOTUS will see the light.