Originally Posted by
totti
Fare classes don't always translate one to one from on airline to another. If T is a deep discounted Y fare class on US than it'll book in a deep discounted LH Y fare class (e.g. L,T,E) and will only earn 125 miles.
I don't know how well L, T and E combine with longhaul flights on one PNR. I think it's also possible that the codeshare would book into U, W or S - some kind of class that LH uses for cheap longhaul tickets (and their connecting segments within Europe).
But as always with codeshares, flying it is really the only way to find out.