Batiks are my preferred fabric choice for Bargello. The batiks without resist printing are perfect for blending and the batiks with resist printing lend great texture. I would avoid batiks that have a large color variance though as you won't be able to plan if the purple dyed section will end up in the green section.
That said ... if you find a great print that will work ... don't be afraid to use it with the batiks. The prints can lend great texture to the overall outcome.
The best thing about using batiks though is the thread count - it absorbs more starch and makes the fabric nice and crisp and much easier to work those wonderful narrow strips that some bargello use.
My avatar is using 99% batiks. The black at the bottom is a screen print and the color immediately above it. The borders are also screen print. The remainder are all batiks ... some with and some without resist print.