If your tomatoes get a little rain it won't hurt them if you get a downpour then turn off your soaker hose for a couple of days until the soil dries a bit. Don't let them get too dry though. Tomatoes like a constant moistness but not sopping wet.

My neighbor grows cherry tomatoes in pots. She doesn't have a soaker hose and she puts mulch on top of the soil around the tomatoes. This ensures the tomatoes don't dry out fast but can stay out in the rain.

Now we live in zone 3 with moderate summer temperatures. If you live in a hot zone you will need that soaker hose to keep them moist. You will have weigh your options and decide what works best for you

The idea is to keep the foliage as dry as possible to prevent diseases. Can't do much about the rain.