Saccharomyces cerevisiae is one of the three non-vertebrates that appear in the main Ensembl database (along with Drosophila melanogaster and Caenorhabditis elegans), used to anchor the gene trees in Ensembl. To find other non-vertebrates, you'll need to used our sister site, Ensembl Genomes. Here you'll find a database for fungi and for bacteria. In Ensembl Genomes, we have the pan-compara analysis, which compares a subset of species from a each of the taxa. Schizosaccharomyces pombe is one of these species, as is human and a number of bacteria. This means that for any gene in S. pombe you can find orthologues in bacteria, human and other species (if they exist).