The recent US Supreme Court case left the issue in legal limbo.
The respective State National Guard units are under state control unless federalized. The C&C of the Texas military, for instance, is the Governor, not the President. As the Washington Post article notes,
"Due to this potential conflict, we are unable to enroll same-sex families . . . at our state-supported facilities until we receive legal clarification," [General] Nichols said. The Texas National Guard clarified in a statement that it has requested guidance from the state's attorney general's office but did not say whether it was consulting with the Pentagon....
The Texas National Guard said Wednesday that its policy will not prevent same-sex spouses from applying for federal benefits. "It is important to note that this is not a denial of benefits, rather it is a processing issue," said agency spokeswoman Lt. Col. Joanne MacGregor.