From a quick reading of the judgment - both.
The judge appears to be saying that until the City of London review is finished and a decision taken then there is nothing that there can be a judicial review of as there hasn't been a decision yet.
Also, the current policy has been in effect for so long that it is too late to have a judicial review of the original decision.
The judgment also says that Sex Matters does not have standing and that it would have been more appropriate for an individual to bring a claim in the County Court. The judge said
[55] In my view the more appropriate person to bring this claim is an individual who says that they have been discriminated against by decisions about access to the Ponds. The starting point of the Claimant’s case is direct discrimination, and the statutory scheme in the Equality Act 2010 is focused on individuals who say they have been treated less favourably.
.
Last year, my DH brought a direct discrimination claim against the WI and the judge is saying here that it should be somebody like my DH who has been personally affected by this.
For example, if a woman wanted to swim in the Men's Pond with it's better facilities (it is larger and has a diving board) then she is not allowed to do so unless she also has the PC of gender reassignment.
So, a trans-identifying woman can swim in the Men's Pond but not any other woman.