I believe the recommendations you mentioned don't specifically pertain to the +1 facility. The "market" alternative which is working is:
https://market.android.com/details?id=PACKAGE_NAME
Nevertheless, I believe you're supposed to use:
https://play.google.com/store/apps/details?id=PACKAGE_NAME
Personally, I switched to the "market" link, because I had a strange "out-of-sync" problem. The number of +1's on Play's website was very different than those inside the app. It looks like the issue has been fixed though and now both links are in sync.
You can test your links here: https://developers.google.com/+/web/+1button/