Rules FAQ
Spend refers to any ability that allows a player to choose to pay gold (e.g. marshalling a card or playing an event) or move gold (e.g. bestow) from their gold pool.
Warship.
During the challenges phase, you may spend gold on Sweet Cersei as if it were in your gold pool.
Reaction: After you win an challenge, move 1 gold from the treasury to Sweet Cersei.
Link: Decklists
Rules FAQ
Spend refers to any ability that allows a player to choose to pay gold (e.g. marshalling a card or playing an event) or move gold (e.g. bestow) from their gold pool.