I bought my dad a round trip ticket to AMS using miles. The US-EU flight is in Business, the EU-US flight is in Economy.

I know that the luggage allowance for Business is 2 bags. The allowance for Economy is one bag.

However, I've had instances where one flight on the itinerary was upgraded to first (domestically) and on the way back when upgrades hadn't cleared yet, it offered me the option to check 3 bags free instead of 2.

Is the reservation smart enough to understand that it's 2 bags there, 1 back, or does the blanket of a partial business ticket extend to everything.