Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: IB+ Gold, TK E+, Hyatt Globalist, Marriott LTP, IHG Diamond
Posts: 14,186
Both IB+ Oro and BA Silver should be getting Group 1. But it doesn't really matter because nobody will stop you boarding with your partner if they have Group 1 printed on their BP.
The problem may well be with IB not recognising your BA number as having elite status.