strange, it worked fine with other plantations nr my 2nd city, and now ive founded a religion the bonus has appeared for that wine plantation nr my captial.
Pantheon behaviour is kinda confusing when full-blown religions start making an appearance.
When you first create a pantheon, all your cities automatically get it. If your city is exposed to any foreign religious pressure at all, it is considered a contested city and you lose your pantheon bonus.
When founding new cities, they all automatically get the pantheon until you establish a full-blown religion. Any cities founded after you establish a religion get nothing; they have to be converted just like any other city. (i.e. missionaries, prophets, or religious pressure)
There's one final quirk about the pantheoon -> full religion transition. Normally, missionaries have a limited strength. They can only convert 5 or 6 citizens. Or maybe even less... I'm not sure of the formula, and if they have to fight other religions, they convert even fewer citizens. However, if a missionary attempts to convert one of your cities with an active pantheon, he automatically converts at least half of the citizens, ensuring that your religion will be the dominant religion after a single conversion attempt. I've converted cities with 16 citizens to my religion with a single conversion attempt when they had my pantheon. Similarly, even if your city is contested, (thanks to foreign religious pressure) your missionaries automatically convert them in a single attempt. If a foregin religion is dominant, your missionaries have to fight for citizens like normal.