Fiona (Jessica Lange) asks that her portrait be hung in her chosen spot and not stored in the basement with "the disgraced Russian witch". This is a reference to Madame Helena Petrona Blavatsky, the Russian-born occultist and founder of Theosophy, which later evolved into the New Age Movement. Blavatsky was charged with fraud and plagiarism by many of her critics.
Fiona (Jessica Lange): "I'm starting to look less Samantha and more Endora every day."
Referencing the 1964-1972 ABC TV series Bewitched (1964), starring Elizabeth Montgomery as a witch, Samantha, who marries a mortal man, Darrin Stephens (Dick York). She vows to forsake her powers and live life as a mortal woman, but is usually called upon to cast spells, usually to cope with her magic-wielding relatives who disapprove of the marriage. Samantha's mother is Endora (Agnes Moorehead), a meddling older witch who disapproves of her husband and makes her feelings clear at every opportunity.
Fiona (Jessica Lange) tells Myrtle (Frances Conroy) that she is going away to Patmos. That is the island the disciple John was exiled to in the Bible and it's where he's said to have written Revelation.
Around 25:07 Fiona asks Myrtle Snow if she remembers, "Levon" the drummer with the band. This is a reference to Levon Helm the drummer of 'The Band', who played at Woodstock, and also had a successful career as a film actor, appearing as Loretta Lynn's father in Coal Miner's Daughter, as Chuck Yeager's friend and colleague Captain Jack Ridley in The Right Stuff, and as a Tennessee firearms expert in Shooter.
As mentioned, Fiona brings up her affair with The Band drummer Levon Helm at Woodstock, who later became an actor. How he connects with Jessica Lange is he co-starred in Coal Miner's Daughter, about Loretta Lynn, and a few years later, Lange played Lynn's friend, singer Patsy Cline in Sweet Dreams. Helm also starred alongside Lange's future husband, Sam Shepard as Chuck Yeager, in The RIght Stuff in 1983.