You don't say how long you have been at this. Try letting the kitten walk around with the dog still restrained. The kitten will probably keep a safe distance from the dog, but you will still have to supervise at first. Often, even though the cat hisses at the dog, she will still return to him, and be interested in him. My own, very old cat still sometimes hisses and swats at my much younger rottweiler.
The dog is a little too rambunctious for the cat sometimes, but they still like each other. The cat just gives a little warning. Also, cats will sometimes swat a dog for no obvious reason. That's just how they are.