In order to put the custom line annotations behind the data points you can use the ZIndex
property of the annotation and set its value to a lower value. For example -200.
Let us know if this solution works for you.
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