"B" is a coach fare despite being labeled a "business" fare. Although an occasional lounge dragon might be fooled, I'm not aware that it should get you into any lounges.
I definitely would take DL to task for rebooking you on a T fare and losing the extra 50% qualifying miles.
The lounges in both Zurich & Berlin are AF lounges. AF limits access to Skyteam departures only.
The lounge info on delta.com does seem to misrepresent this, unless they have an affiliate arrangement with the AF lounge.
Originally Posted by
ShopAround
I've been in the lounge in Berlin and believe me, you didn't miss anything. It's small, not much in the way of food or drink and no free internet access. Was hardly worth bothering with.
I've used the lounge at TXL (Berlin Tegel) several times this year. Food/snack/drink/liquor selection is better than Sky Club, definitely better than what they've downgraded the WorldClubs to. Having the restrooms 4 levels down in the basement does stink (and they are pay toilets, too, although you can find non-pay restrooms closer to the gates).