Wikipedia says sci-fi is:
Science fiction is a genre of fiction dealing with imaginary but more or less plausible (or at least non-supernatural) content such as future settings, futuristic science and technology, space travel, parallel universes, aliens, and paranormal abilities. Exploring the consequences of scientific innovations is one purpose of science fiction, making it a "literature of ideas".
Now I would deem Otherlands as being a parallel universe and I certainly write about both worlds as being set in this time period or potentially in the future.
But then fantasy is:
Fantasy is a genre of fiction that commonly uses magic and other supernatural phenomena as a primary element of plot, theme, or setting. Many works within the genre take place in imaginary worlds where magic is common. Fantasy is generally distinguished from the genre of science fiction by the expectation that it steers clear of scientific themes, though there is a great deal of overlap between the two, both of which are subgenres of speculative fiction.