British Airways very rarely offers status matches, but they’re currently offering to match bmi Diamond Club elites with addresses in Belgium, Israel, Ukraine, and the Netherlands — places that bmi is pulling out of servicing.
Even British Airways Silver members get lounge access, including when flying on partners like American. And British Airways Gold members get access to British Airways first class lounges — even when they aren’t flying BA. This saved me one time in Milan, where Alitalia’s Boticelli lounge is one of the worst pits I’ve ever experienced (fortunately they had shower kits; unfortunately there was no hot water and the drain didn’t work and the line to get a coffee was 10 minuts long).
If you have a bmi Gold card, this may be a good opportunity for a year of BA Gold status and BA lounges (provided you are based at or transit a terminal with a dedicated BA lounge) provided you have access to an address in Israel, Belgium, Ukraine, or the Netherlands.