RNE / Uniao Estavel (São Paulo)

I've recently moved to SP with my boyfriend - he's the an administrator of a local company and based on this has just got his RNE (although not a work visa it does the same thing) . We've got uniao estavel and I've heard that I can therefore get a permanent visa on the back of his RNE - does anyone else have any experience in this or recommendations for how to proceed with the process?
Any suggestions massively appreciated
Thanks
Gabrielle