Actually I did end up watering the pots today because they felt bone dry and I'm not sure there are enough roots reaching the growbag YET(!) to draw the water up into the plants. I only planted them into the bags on Tuesday.
They're not going to give up easily, so just water them when you think they need some, and leave them if they don't!
Just a thought, but does your growbag have small drainage holes in the sides, about an inch up from the bottom?
It's helpful to have these just to let excess water out if they get too much! If the haven't, you'll want to make them by shoving a knife in the sides, low down, just a short stab to break the plastic, and that'll do the job! You'll then have some sort or reservoir if they get really hot and dry, as some water will have collected right at the bottom, ready to be taken up as necessary!
Toms are pretty good at telling you when they need a drink (aren't we all..:0), so never fear, you'll know when they have to be watered and then feeding can start when the first truss has set with tiny green toms the size of a pea, under the flowers.
Don't forget to pinch out the tiny side-shoots if you want to grow them as a cordon (just one big stem), and as they're inside, you may be able to get to six trusses, but five may be ample, and especially if the summer gets shortened for any reason. Five trusses are the norm for outside anyway, and I sometimes just do four if the plant looks a bit tired - 'know the feeling'..;0)
Keep going, they look just fine to me!