Not practically, unless you are really perverse.
Its not clear why you might want to do this (it won't allow you to get more then the maximum speed of your connection - ignoring the advantages of compression if enabled on a VPN, a VPN adds overhead and makes things slower - both throughput and latency wise then a raw pipe.)
I believe its not practical to do this for 2 reasons -
The tunnel server will have a single end point IP and port/set of ports/protocol,
and the PC will have a single IP address, thus causing problems with having 2
connections. (You may be able to overcome this with some types of VPN, for example
UDP tunnels with OpenVPN might just work, but I doubt you will have any luck with,
for example PPTP)
The routing will be messy and complicated - you would need to work out how to balance
the load doing source routing and possibly other tricks.
So, yes, it might just be doable in some cases, but I can't see a reason why you would do it practically.