Yes, you are correct, we do not have a range bar series for RadChartView yet. We will add support for this type of series for the next official release, scheduled for October.
However, I would like to point out that in case you have date time x-axis and categorical y-axis, you would not be able to display the line series as in the attached picture. Basically, you need a linear y-axis so that the data points have correct position according to the y-axis. The labels that you want to show seem more like a legend in this case.
You can take a look at our RadTimeline and RadGanttView controls, in case one of these controls better suits your needs:
the Telerik team