They can be inconsistent about this, and the mixed classes across the booking seem to mess them up, even though if on the same booking, the same allowance should apply for all segments.
Had something similar with AF recently, where the entire booking was in J (paid for fare, not miles) and even my e-ticket receipt showed 3x32kg (2 for J and 1 more for Platinum with DL). I had printed all that out just in case. I get to the airport for segment 1 which is booked with a J code but only offers Y service (NCE-ORY to be specific), with one piece that’s around 30kg and another that’s only 5kg… so very well under limits. The check-in agent is saying I need to pay the overweight fee. I show him my booking that shows 3x32 but he says it doesn’t apply because ORY is only economy service. He also says it was a mistake that the flight was issued in J booking class. I said that if it’s a mistake, AF should honour their original selling conditions, to which he said that’s not what he said… it wasn’t an AF mistake, it was MY mistake to buy the fare on the AF web site. And mind you this was not at all a cheap flight or a mistake fare or anything of the sort. It was your average EUR1000 intra-Europe fare.
After some back and forth he offers to move me without cost to the CDG flight if I want “business” but by this point I just want to be along my way. He finally says “as an exception” he will take the bag without charging an overweight. Geez thanks.