Unless the bedding is specifically part of the mesh (eg. some beds from Sims In Paris or Peggy) it is a recolour of one of the base game beds. So curtains that you find that are repositoried to take their textures from bedding would draw their textures from all bedding that you have available in your game.
It sounds like you might be talking about CTNutmegger's Dazzle Drapes, which you can find as part of sets
here. Just take a look through there to see if you recognise those, but it does say that they aer repositoried to take their textures from bedding.
There is also
this set. In the description it quite clearly explains that the curtains are repositoried to take their textures from the Colonial Ironwood Bed and thus will draw textures from all bedding you have in your game - both Maxis ones and downloaded ones. This is, as I already said, also true for other repositoried curtains.
And Huge Lunatic has a couple more repositoried curtains
here.
If you are looking for a specific set it would be helpful to know what the curtains looked like. Were they hanging straight to the floor? Drawn to the sides like some of the drapes you have been linked to? What exactly are we looking for, other than any random item that is categorised under deco>curtains and is repositoried to bedding?