The victory is limited. Although the appeals court sided with the administration, other federal courts issued injunctions against the policy, which applied nationwide. The administration already has asked the Supreme Court to weigh in on the issue.
Usually (as I understand it, NOT being in the legal profession) Circuit Court rulings are binding within the territory of the circuit, unless the USSC rules on it (and maybe if they decline review). I'm not clear, though whether the DC Circuit is territory based, and whether its rulings are binding nation wide for Federal actions outside the DC Circuit.
That said, the USSC tends to take on cases where Circuit Court rulings conflict. So the chances the USSC will take this case are in the high-certainty range, I think. IIRC, the particulars of this "ban" are based on the impracticality of getting appropriate meds and medicinal/psychological treatments to remoter stations and postings in a timely manner, making a
Trans service member a potential liability at critical times..