So in summary:
20% of your investment went into capitalising the asset you now hold
80% of your investment went into capitalising a private company in which you didn't get any shares
Like I say, that's just my understanding of the current equity balance of the ICO. I'm happy to be corrected if wrong.
I think the 20/80 rules only apply to the last 147K ETH that poured into the ICO that was above their intended 250K ETH cap. So I think the correct way to look at it is that (250+0.2*147)/397 = 70% of your donation went into capitalizing an asset you now hold. The remaining 30% went to an unplanned, "ex post facto" fund whose assets you now have no claim over. For the next 2 years this new fund will purchase tokens (at a price that gives zero profit to the public sellers) and give those tokens back to the Bancor Network that issued them.