Yeast Blend Harvest and Starter?

I got a bottle of my buddy's Hibiscus Ginger Saison (AHS kit and quite tasty!). He used the WLP568 Saison blend. I harvested the yeast from the bottle and have a starter going with the harvested yeast. I'm going to use the yeast on a Saison on Sunday

I started thinking, since it's a blend, are all of the yeast varieties growing together? Or is one of them growing better (or did one grow better in the original batch)?

According to the White's on Jamil's Saison show, the yeast varieties work well together and none of them destroy or dominate the others.

Has anyone harvested yeast blends before? Any input?

I do this with my house blend of Cali Ale Yeast and Koelsch yeast. They do tend to "drift" over multiple generations (mostly because of differences in flocculation and alcohol tolerance), but the effect is fairly subtle for the first few generations when repitching onto the yeast cake or harvesting/washing the yeast. Building it up from the bottle is likely to increase the odds of one yeast becoming dominant over the other because of the very small sample size and relatively harsh environment they are in, but this being a second generation harvest, it'll probably be perfectly fine.

Cheers, and good luck with your experiment!