It depends on the bottle size, but the short answer is absolutely!!! If those are 8 oz. bottles of water, you should probably double that at least.
Here's a quick link to some info. about water and a water calculator that will tell you how much to drink daily based on your weight:
http://www.myfit.ca/water.asp
One of the best things about the right amount of water intake is that it helps to keep your brain working better (no really, there's research) and it flushes out toxins from your body. When you are eating poorly and not exercising (like I have been) there are tons of toxins built up in your body. It was amazing to me how much weight I took off just from drinking more water. You may actually be retaining water simply because you are not getting enough water intake.
If you are having trouble getting enough water in (like I do), you can try squeezing some lemon juice (from a fresh lemon, not that bottled stuff) into your water and it seems to help the taste as well as acting to remove toxins. After much experimentation, I have had to completely avoid all drink mixes because they always end up making me drink less water. Sipping also does not work for me. I just have to chug a half a bottle of water (about 8 oz.) every hour or so in order to get in enough water. It seems like a lot, but you get used to it and I feel so much better for this simple change.