As far as I'm concerned, it's not. It's hard to trap it on Foot.ie because it's so prevalent, but I try to tackle people on it when I get a chance. If you or anyone else see someone using those terms on Foot.ie, you should click the Report This Post icon at the top-right of the post.
http://foot.ie/images/buttons/report.gif
The term "banter" is used both at games and here on Foot.ie far too much as an excuse for ignorant behaviour. I don't like it one bit, and I have a major problem with the word because of that.
adam