Did the revelations in the Bible already happen?
If by 'revelations' you mean fulfilled prophecy, there are a vast amount of fulfilled revelations in the Bible. Some have been completely fulfilled while others are a contiunual process of fulfillment.
If by 'revelations' you mean the (Revelation) of God given to Christ and Who then gives it to John in the book of (Revelation), (Rev. 1:1), I would say the vast majority are yet future. Distinction must always be made concerning the things 'which thou hast seen', and the 'things which are', and the 'things which shall be hereafter'. (Rev. 1:19)
Lees