It is a bit painful to add error bars to a grouped bar graph. Here is a small example that you may be able to adapt to your purpose:
mean_velocity = [5 6 7; 8 9 10]; % mean velocity
std_velocity = randn(2,3); % standard deviation of velocity
figure
hold on
hb = bar(1:3,mean_velocity');
% For each set of bars, find the centers of the bars, and write error bars
pause(0.1); %pause allows the figure to be created
for ib = 1:numel(hb)
%XData property is the tick labels/group centers; XOffset is the offset
%of each distinct group
xData = hb(ib).XData+hb(ib).XOffset;
errorbar(xData,mean_velocity(ib,:),std_velocity(ib,:),'k.')
end
I got that code from this question I asked in the past.
Here is the result:
