Oh, my gosh, I went through the same thing with my now 18-month-old daughter! It didn't matter whether it was formula, baby-food, water, etc. You name it, she would spit it up. We tried everything--several different formulas, more cereal--less cereal, different feeding positions, different reflux meds, etc. The only thing that seemed to help was Chiropractic adjustments. Even so, the problem did not completely go away. I also changed to "Slow flow" nipples because she drank her bottles so fast. It slowed her down but didn't stop the spitting up.
I was told by my doctor, "Some babies just spit up until they walk." I thought there had to be something else going on. Well, once she started walking, she stopped spitting up! I couldn't believe it!?! It was the craziest thing! I will never forget how I felt the first day I picked her up at daycare and she was wearing the same outfit I dropped her off in that morning! What a monumentous occasion! Then, all of a sudden, we were making it whole weeks without using extra clothes. I was dumbfounded the first time I did laundry and had absolutely nothing to soak! A lot of the time, I would have two soaker bins in use at the same time so it was a big deal to realize I didn't have anything to soak anymore!
We had a very large fleece blanket that was on the living room floor at all times (unless it was in the wash after she was in bed) and it was her "boundary." Once she started rolling and crawling, it became a little harder to keep her on the blanket but it still served to catch most of the surprises. We also had a large stack of towels, one on the shoulder at all times and, at feedings, one laying on the front of her as well. I sure don't miss that part of her infancy! So, if you can hang in there a few more months, it really will get better!