Is this bacterial wilt?

[rsg2001]

See the photo. It was fine this morning and early in the afternoon, and when I looked at it at 4pm half the Costoluto Genovese was badly wilting. Not the whole plant. At 10 this evening part of the plant looked like it was starting to recover. I guess that I'll know more in the a.m.

CG shares a 3-foot by 3-foot self watering planter with several other tomatoes. None of the other ones show this symptom. I use Gardener's Supply self-watering container mix -- which I've had good experience with for years. I replaced half of it this year. None of the plants last year showed any symptoms like this in this container either. As it's been hot as blazes for an extended period of time, I've been diligent about keeping the water reservoirs replenished. They get about 6 and a half to seven hours of sunlight a day.

CG has about 20 tomatoes in various stages coming in.

I did do one thing yesterday - I 'side dressed' each of the plants in the container with Tomato Tone granular fertilizer. Could that have caused this?