I don't know enough about the VC Materials but in my time of laptop repairs, I see this a lot in the older Mac screens and if it is the same thing, what you've done is essentially gone through the top coating - And usually when we ask about it it is where people have used abrasive liquids like glass cleaner.
In regards to the mac, we end up removing the entire coating with a fair bit of elbow grease and baby wipes and...well abrasive liquids like windex. The end result is a very clean screen in most cases but the difference between having the anti-glare coating and not is very obvious.
Lets see what others say - hopefully someone who has had the same issue with the actual VC can chime in as laptop screens I suspect are probably a little more better in handling pressure than the VC!
Too late now but in future, what I do is breathe on the VC and wipe - not the more pleasant way of doing it but avoids this - I wonder if the MMI screen cleaner Audi sell is any good