FlyerTalk Evangelist and Ambassador: The British Airways Club
Join Date: Jun 2008
Location: Somewhere between 0 and 13,000 metres high
Programs: AF/KL Life Plat, BA GGL+GfL, ALL Diam, Hilton Diam, Marriott Gold, blablablah, etc
Posts: 33,174
Yes the most generous allowance applies to the full itinerary (with all legacy airlines, this is not a BA thing at all, it is an old IATA rule) as long as it is all on one booking, and in a way I am surprised that the YUL-AMS and AMS-BRU are allowed as combinable (or is it just counting as a one way YUL-BRU via CDG and AMS?).
And yes, mileage is determined independently for each segment.