Hi Jay,
There is an example in ChartDirector demonstrating tooltips on both the data points and the legend entries. May be you can use it as a reference. (The sample code shows a line chart, but you can easily change the addLineLayer to addBarLayer.)
http://www.advsofteng.com/doc/cdnet.htm#customclickable.htm
Hope this can help.
Regards
Peter Kwan |