Originally Posted by
nini_su
Can confirm as of two weeks ago. I even managed to use my SAS Eurobonus points to bid on the upgrade and didn't have to re-enter my Miles+Bonus number or anything and everything got correctly credited (200% to A3).
This is an interesting data point! In the past I upgraded an LH flight using M&M miles (not through the bidding system), and I had to fight tooth and nail to eventually get A3 to credit the miles for the original booking class.
Note that for SK, getting the additional miles from the upgraded booking class only applies if you upgrade using Plusgrade (bidding for an upgrade up to 48 hours in advance). If you upgrade using cash or points at check in, you do not get EuroBonus points according to the upgraded class of service, and I assume this also applies if crediting to M+B.