It is actually Hankyu Sannomiya station, different from the JR Sannomiya. It is about a 5 mins walk from JR Sannomiya station. As for Onsen, you can try going to Kinosaki area, famous for the onsen around Kobe area, from there can even take the ropeway up to mount rokko for one of the supposedly best 3 night views of Japan.
I also went to Steakland,hmm haha but that is the only one I tried so not sure if it is really good compared to the rest. But haha it is already very good enough for me even I just ordered the most basic 4700 Yen starting grade kobe beef