I would not expect the chlorine in the water to pose any problems because normal tap water is chlorinated although to a much lower extend. Some of the joint of the tub are probably sealed with rubber or silicone washers so if these are safe so would your toys. I wouldn't leave the toys sitting around in the water though because it may cause surface damage after multiple hours.
Toys are considered "waterproof" if you can use them in the bath. They probably haven't been tested in front of a strong waterjet, like you would have in a hot tub, so it would be your own risk. Maybe use the toys with the jets and bubble off if you're worried or keep them out of the direct flow.
Do bear in mind that using toys internally is more likely to cause bacterial problems when in water, especially dirty water. This is why sex isn't recommended when swimming in the sea. You are also more likely to require additional lube because it can wash away faster than your body can produce it. If you are doing it on a reasonably regular basis, you may want to upgrade the water filtration unit and invest in a UV steriliation unit.