I went through the website and uploaded a screenshot of my Virgin gold account - it didn't work the first times - kept on saying it couldn't verify all the information. So I managed to take a screenshot of my membership card on apple wallet, it wasn't the best quality but it immediately approved me for Gold. I did notice that BA gold get United Platinum so I reached out to United and the representative said it is possible but to email customer service. So I did that, just waiting for a reply. I will update if successful. Safe travels.