Greet Philologus, Julia, Nereus and his sister, and Olympas, and all the saints who are with them.
Romans 16:15 ESV

These were probably leaders of one or more other home assemblies. That Paul includes two women here--one unnamed--could indicate that the assemblies greeted in v14 and v15 had evolved minor differences in their practices. If these do represent different home assemblies, then those in v14 might have been more patriarchal in their leadership philosophy, while those of v15 might have been more complementarian or even egalitarian.

Paul’s didn’t write this letter to give advice on how to structure the leadership of an assembly, so I don’t think we can read anything into the fact that he didn’t comment on these differences. Especially since I’m only speculating about why these particular names are grouped together.