PostgreSQL proxying

Hello folks! :-)
hope I'm not OT here
Need an advise here.

I have a PostgreSQL cluster that should be accessed in two ways:
- By a Web Services system (always same host in my vLAN, and that is simple)
- By a replicator (any host, with unpredictable IP)

In my previous configuration I had a VPN, and I could say that all users
came from 10.x.x.x/x, however a private IP range.

Now I experienced some bad habits in connecting to VPN from userss (no
connection at all, timeouts, peculiar configs to be done on particular
systems, etc) and I was thinking about getting rid of VPN and having
connections using SSL and a proxy, leaving VPN only for us and our
administration purposes.
I already have pgbouncer installed on a server near the one running
postgres cluster and I know that pgbouncer should be considered like a
proxy, but as for your experience should it be sufficiently secure?

Thanks in advance
Moreno.-