In Rev 5, the souls under that alter ask, "How long?", clearly showing God's wrath hasn't started yet. Actually, God's wrath doesn't occur until the first bowl of wrath, right after the seventh and LAST trumpet. Revelation 6, actually:
9And when the Lamb opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the testimony they had upheld. 10And they cried out in a loud voice, “How long, O Lord, holy and true, until You judge those who live on the earth and avenge our blood?” 11Then each of them was given a white robe and told to rest a little while longer, until the full number of their fellow servants, their brothers, were killed, just as they had been killed.
There will be people who turn to Christ in faith throughout the Tribulation period and who are martyred for it. It sounds like there will be quite a bit of the wrath of God poured out upon the earth even before the seven bowls of the wrath of God spoken of in Revelation 15-17. The Seven Seals included war, famine, death and terror.