For most people its the download speed that matters as general users download a lot more than they upload. The only time this isn't true is if you're sending a lot of data/files through the internet, i.e. you're running a server.
That being said, your speeds sound fantastic for household speeds. As for what the speed of the VPN will be determined by, if I'm not mistaken its a combination of both your connection with the VPN and the VPN with the rest of the world, where the slowest of the two will be the bottleneck. However, my VPN experience is rather limited.