The phrase 'unto him that sits upon the throne and upon the lamb' tells us that the Holy Spirit is the one who deserves 'blessing and honour and glory and power' for His work in the lamb, Christ Jesus. Note the use of the words 'unto' and 'upon'. We give worship unto the Holy Spirit through worshipping Christ Jesus upon whom the Holy Spirit has given glory.
Many people attempt to find the Lord and worship Him. But the Holy Spirit (God) cannot be found except through the person of Jesus who is the Strait Gate and the Narrow Way.
Every creature that has ever lived will one day praise The Majesty and His lamb.
Jesus is no longer a lamb. He is Mighty God. When reference is made of Him on the throne and Him as the lamb, we need to understand that the one on the throne is the lamb. But His role as lamb is finished.