I found when I was browsing for tea in HK in December that the high grade Dragonwell (Long Jing/Lung Jing) carried by the few shops I visited was from Shifeng (Lion Peak) near the West Lake that all Long Jing is supposed to come from. I was told it is a single farm but either must be enormous or some sort of network qualifying as a brand of sorts.
Ten Fu's network is now quite also large. A friend told me recently that he was told by an employee in Sichuan that they have moved largely into tea production and now own many of the farms that they sell tea from. That might also qualify as a brand. When I lived in China and could afford it, I mostly bought from them.
Note, Ten Fu is also known as Ten Ren and sometimes also as Tian Fu.
Regards,
Joel