I commute via bike (20 miles round trip) and keep busting spokes on the rear wheel. Busted one again last night on my way home I think it's the 10th or 11th I've had to replace. They seem to break when I'm climbing and stand up in the pedals. With loaded pannier bags. Bad batch of spokes? Anyone had a similar problem, I'm thinking the best solution is a wheel rebuild?

yes rebuild the wheel , and makes sure the spokes are set the right tension, because of the wight the bike is carrying and the tension is low is why you are busting spokes here.

If the spokes that are breaking are non-driveside, non pulling spokes, then the spoke tension is too low.

You have broken so many spokes that it is certain that all of the spokes are damaged. No more repairs...........rebuild.

What kind of wheel? If it's less than 32 spokes, you're going to continue to have the problem. With panniers, depending on how much weight is in them, you want more spoke and a fatter tire, like at least a 28 and up to 35c.

32 hole heavy duty WTB rims, running 700x28 vittoria randonneur cross tires.
It's getting rebuilt next week.