I'm a subscriber and I have not yet found they do, but on the plus side they do have fax to voicemail that I have tested and it works. I sent a test from online fax service and was able to download it to my email client inbox. I think this is one of the OBiEXTRA features.
I am spoofing my GV number on my PhonePower account, so I can still send texts using GV.