(author here) Here's a quick implementation of error bars for d3.compose [1]. The general goal of d3.compose was to provide the foundation for creating reusable charts and components while keeping the standard library of charts/components relatively small and focused. With that said, there are plenty of charts/components in the pipeline (scatter, area, and callout to name a few) and I'll make sure error bars are added as well.
1: http://bl.ocks.org/timhall/87aee92992f6f7892a1d