Assuming the VPN solution is solid, the end result is an encrypted session, anyway, so unless someone compromises your actual host (your laptop), your data should be encrypted, via VPN, as it crosses the wireless.
Just that I've seen a few VPN solutions that I HAVE foind holes in, where I was able to pull off some wizardry, and hack / gather the end-users' data, unencrypted. So the point of the last sentence was to make sure your VPN solution is solid, too. Not ALL have holes. But I prefer a VPN solution that uses a 'full client', when possible, versus one that is established solely across a browser session, when it's initiated. When I said 'web-based', I was referring to the latter (the browser- based / initiated ones)
Edit: and the VPN situation would apply, regardless of Jetpack or McD's wireless, so don't base the original decision, solely on VPN.
"All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." - Sun Tzu, 'The Art of War'
OSCE, OSCP , GPEN, C|EH