I Am Completely Serious

Personally, I always think of Anne Rice's "Beauty" books as fantasy, even if the only bit of magic we get is the fairy-tale setup at the beginning, because they are such a stew of NOTHING WORKS THAT WAY! that trying to think of them as realistic novels involving real humans just BREAKS MY BRAIN.

For more yaoi manga -- Yamane Ayano's The Crimson Spell, a medievaloid-Fauxropean high fantasy world in which a prince is forced to take up a cursed sword that transforms into a vicious and lustful demon at night, teams up with a bishie sorceror to try to find a way to lift the curse, and Sexy Magical Dubcon Bondage Hijinks ensue (along with a rather pleasantly surprising amount of plot and character development). Anyone who thinks Hakkai in his unlimitered youkai form is unbearably hot will likely find demon!Val extremely Relevant To Their Interests; this one is relatively low on the SM side of things and heavier on the BD -- there are magical chains, magic non-corporeal bondage, magic tentacles, I think there was even a magical non-corporeal cockring at one point?

(Also doesn't Higuri You tend to have a fair bit of BDSM-ey M/M stuff in her work? Ludwig II certainly did and I've heard Gorgeous Carat starts out with a rather extreme whipping scene, although neither probably counts as fantasy except via the "mangaka treats Europe like a made-up world" sort of technicality.)

For more vampires, of various orientations -- author Patrick Califia, who's noted for both non-fiction BDSM/sexuality writing and primarily-lesbian BDSM erotica, has a few interrelated short stories and one related novel that may be of interest, although some are likely to be hard to find. "The Vampire", anthologized in Daughters of Darkness: Lesbian Vampire Tales, involves some serious singletail whip play, a butch lesbian vampire top, and an aggressively seductive femme who is more than she seems; "Parting Is Such Sweet Sorrow", anthologized in Sons of Darkness: Tales of Men, Blood, and Immortality involves a switchy bisexual male vampire, there's also a seriously dark (dub/non-con, lots of potentially triggery material about past abuse and rape) lesbian piece featuring the vengeful half-sister of the protagonist of "Parting..." anthologized in Love In Vein II; both Ulric and Adolpha reappear in the later novel Mortal Companion, although the primary relationship in this one is M/F.

If you'll take sort of fairy-tale retellings as fantasy, Califia's short story "Blood and Silver" (anthologized in both No Mercy and Blood and Silver) is a BDSM version of Little Red Riding Hood as a werewolf lesbian dominatrix. I SWEAR IT'S WORLDS BETTER THAN THAT PROBABLY SOUNDS, HONEST.

I haven't yet read them myself, but Artemis Oakgrove's 1980s "Throne Trilogy" (The Raging Peace, Dreams of Vengeance, and Throne of Council is supposed to be lesbian BDSM fantasy. And for more recent works, I would very very surprised if you couldn't find at least a few lesbian-BDSM-fantasy titles in Circlet Press' back catalog, since erotic F&SF is their bread and butter.