Normally, you should be able to control the resource column width with the RowHeaderWidth property. However, there is a glitch currently with this property and until we fix it I suggest you use the following css:
.rsTimelineView .rsVerticalHeaderTable div
the Telerik team
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? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items.