I think you will be fine. NC State says 5.5 to 7.5 for tomatoes:
http://www.ces.ncsu.edu/depts/hort/c.../pHplants.html
Every nutrient that a plant needs has a spectrum on the ph scale in which it is available to the plant. The spectrums overlap the most at about 6.5, but that doesn't mean you will notice any difference with your plants.