Sleeri, the best book I know of that identifies the 10 host species of anemone and the corresponding 28 species of clownfish, is Fautin and Allen's Clownfish and Host Anemone Field Guide.
As an example, BTAs host several species of clownfish, but a few clowns, such as tomato and maroons, are only hosted by BTAs in nature. Magnificas host percs and ocellaris and several other species in the wild. Some such as pizza anemones only host clarkii, etc. Clarkii is the only clown that associates with all of the host species.
Anyway, lots of information available on natural pairings--not all accurate. Fautin and Allen is the best resource though, that I'm aware.
Although this information has been around for many years, on an almost weekly (seems daily) basis someone is complaining that their clownfish will not be hosted by their anemone. They go on to say they have an occelaris or percula with a bta..... Those of us who have kept anemones and clowns for years then explain the importance of natural pairings, BUT how often times clowns will go to non-natural hosts such as mushrooms, leather corals, non-natural host anemones, or anemones that never host clowns in the wild(e.g., condylactis).