Greetings.
In Battlegrounds, Tavern Spell ‘Dreamer’s Embrance’ generated by greater trinket called “Essence of Dreams” doesn’t interact with Tae’thelan’s Hero Power Buddy “Reliquary Attendant”. You see, despite it being the first spell I cast that turn, Reliquary Attendant actually doesn’t trigger and instead keeps its ability active until another Tavern Spell is played. But somehow Dreamer’s Embrance spells bought from the Tavern can proc normally with Reliquary Attendant.
I believe spells generated by Essence of Dreams doesn’t poke or trigger “cast-related” minions. There is another thread pointing this issue but the minion in question is Nalaa the Redeemer instead of Reliquary Attendant.
Have a nice day!