I've said this about a dozen times before elsewhere, but I reckon the Kate Bush/Tori Amos connection is really misleading. They're much less alike than people assume, and the ways in which they can be alike (e.g. shared use of the piano, occasionally odd lyrics) are so broad that the connection becomes meaningless - e.g. only a minority of Kate's music is focused around piano whereas with Tori the piano is almost always as central as her vocals, and anyway their styles of playing are very different; lyrically/thematically Tori has always been Stevie Nicks meets Joni Mitchell meets Laura Nyro with a dash of Sinead O'Connor, with very little in common with Kate.
It's something about female performers, I think, that people conflate them so quickly when male equivalents would be considered to belong to entirely different traditions, lineages and even genres from one another.