The champagne in dreams is associated with the celebrations and achievements the one has obtained. If you saw the champagne that was opened, then according to Freud it relates to the sexual intercourse.
Dream dictionary: Champagne dream meanings
If you drink it, it announces satisfaction and joy of living.
…Dreaming of drawing corks at a banquet, signifies that you will soon enter a state of prosperity, in which you will revel in happiness of the most select kind. Dreaming of medicine corks, denotes sickness and wasted energies. Dreaming of seeing a fishing cork resting on clear water, denotes success. If water is disturbed you will be annoyed by unprincipled persons. Dreaming that you are corking bottles, denotes a well organized business and system in your living. For a young woman Dreaming of drawing champagne corks, indicates she will have a gay and handsome lover who will lavish much attention and money on her. She should look well to her reputation and listen to the warning of parents after this dream….
…as I beat and prodded it against the jagged edges of my teeth. But all to no purpose; my head remained full and my stomach empty.”A whole lifetime seemed to pass in this tantalising, agonising manner, and then into the room, in Indian file, stalked all my friends and relations, each carrying in their hands a champagne glass. My uncle, who had been dead and buried at the very least thirty years, headed the procession. Walking solemnly up to me, he took hold of my nose, twisted it round like a tap, and down through my foaming mouth poured the whiskey. As soon as his glass was full he raised it above his head, and exclaimed in a sepulchral voice, ‘ Health! Health! Health!’ to which all the company in chorus responded ‘ Amen! Amen! Amen!’ One after another my relatives and friends followed his example, and twisted my nose…
…Dreaming of hosting a banquet and uncorking bottles to serve people hints that soon the dreamer will enjoy benefits that will improve his or her economic and social conditions. Dreaming of opening jars or medicine bottles suggests that the dreamer is losing energy, which hints illness. Dreaming of a fishing rod cork floating in the water indicates clean and quiet successes nearby. When the water is dirty and worse if its agitated, indicates that some unscrupulous people will produce different ailments and annoyance, perhaps through blackmail. Dreaming of corking bottles indicates that the dreamer is handling well all his or her affairs. A young woman who dreams of uncorking bottles of champagne, hints that she will soon be approached by a lover who has a good economic position, but will question the reputation of the dreamer. This dream is a warning. Dreaming of a corkscrew implies being dissatisfied with…