We do have a specific Chart type called "bar" that will render to column Chart in the same why and correctly calculate the Tooltip position. Modifying the Chart with CSS is not recommendedas it is an SVG element:
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items