Yes and no.  I have lived in areas that have had 7.8pH water and areas with 6.5pH water.  Plus some well waters and other town water supplies may vary more or less.  You then use buffers to soften the water in your home if they vary that much.  Some of the buffers and metals will impact the response of the yeast.  7.0pH is the best starting point but you will need to have GH and KH in the 5-6 degree range for best results.  10-15 hardness is more like well water and may slow the process.  Regardless it will probably work but I'm just giving suggestions for optimum response for those that do not like waiting 3 days for CO2 to happen.