Yep When I was Silver, I always got lounge, extra baggage allowance, and main cabin extra seats in Basic Economy, and Group 3 boarding. Make sure you don't book as a BA codeshare, as the AA flights inherit baggage allowance from the marketing carrier (not the operating carrier). It can be a hassle when getting an IB codeshare on AA metal basic economy, but not as much as BA codeshare on AA metal basic economy (at least, it was always a hassle ex-DUB).