Just my $.02 - We print dye sub for exhibit graphics and have been following the progress of Latex on Fabric as a solution to eventually replace the equipment we have now and streamline the process. The ink rub off is our biggest beef at this time. Coatings are the key to latex inks staying on the fabric, and there are several companies I've talked to that are developing solutions alongside HP to come up with solutions. The one I've been most impressed with so far is TVF fabrics. Even with some of the coatings they are developing now, they have recommended heat setting it (with a flatbed or rotary heat press) which "reduces" the rub off. For us, that's not enough because our fabric graphics are used at multiple tradeshows and folded up for shipment to each show. If we have a large fabric graphic with lots of white or light colors and it encounters enough friction to abrade against itself on the printed side, there's going to be ink rub off and that doesn't work for us. In the right situation with the right fabric formulated to be run on a latex, I think that printing on Latex is fine for fabrics, and you can see some beautiful examples online and at the industry shows.
In your situation to make rope bags, I don't think that you'll be able to make even a coated fabric work without some rub off at this time. If you're set on having printed fabric to make the bags, I would simply outsource the printing of the fabric to a wholesale dye sub printer. I can get fabric printed and sublimated and left on the roll for us to do the finishing for $3.00/sq ft. locally in Atlanta. Basic finishing would cost me $4/sq ft. Merritt has competitive pricing as well, but the shipping costs from the Northeast didn't make the project they quoted for me feasible.
Let me know if I can be of any further help/advice.