Todd, I plant my tomato plants about 36" apart in the rows, farther is better especially for grape tomatoes. I plant two rows 36" apart, then a walk way then two rows 36" apart and so on. I usually don't make the walkway wide enough. You'd think that after gardening extensively for 15 years I'd figure that out.
Peppers go in 18" apart in rows 18" apart. I believe the "mushroom fertilizer" is composted manure. How many tomato plants did you plant and what variety? Excepting the garlic, which was planted last fall, I didn't plant a garden this year so that I could concentrate on some other projects like refurbishing Cub Cadets and putting in a wildlife food plot at my parents farm. Sure do miss fresh picked tomatoes for BLTs and burgers.