Originally Posted by
whiskey_sk
Based on that quote W should be upgradeable by 2 evouchers to business, but not by 1 evoucher to premium economy. Or am I reading it wrong?
It sounds like I'm reading it as you are...
If in W, then can't ever upgrade to Premium economy. But can upgrade to business with: 1 eVoucher for European flights to/from Poland, or 2 eVouchers if worldwide to/from Poland. If already in Premium economy, can upgrade to business with 1 eVoucher for any flight to/from Poland. If Poland is not involved somehow, can't upgrade with eVouchers.
At least that's my interpretation.