Stepping up Supplication Dregs

I had one bottle of Supplication at a bar, got some tinfoil and covered the top of the bottle to try and grow the dregs. I made a 200mL starter, flamed the top of the bottle and poured the dregs in (btw, I found out that if you don't let the bottle cool, it cracks if it's touched by the flask).

It's been a week, it smells a little sour, but I wasn't able to see anything happen. I'm assuming the rockpile wine yeast have eaten some sugars by now.

Should I leave it for a while for the brett & other bugs to eat and grow as well, or should I try stepping up again?

If it were me I would just add the dregs to something already fermented with a primary strain. Like you said you don't want the Rockpile yeast to grow too much. You only really want the bugs from that beauty.

Does anyone know if the rockpile yeast is competitive?