After directing all venerations to Allah, we proceed to say, والصلوات والطيبات usually translated as, “and all prayers, and all goodness.”
The word صلوات refers to prayers, be they obligatory or voluntary. Under this word would also come all supplications and every act of worship in general; we are saying they should be directed to Allah alone, for He is the only One that deserves them, and they rightfully belong only to Him.
The word طيبات refers to all good and beautiful things, both related to Allah and to the deeds of His servants, be they by way of words or conduct.
So when we say والصلوات والطيبات what we are essentially saying is, “and in addition to every veneration being for You alone, so is every form of prayer - be it a supplication or a physical acto of prayer, for You alone. And likewise, every good and beatiful word, action, feeling and state is dedicated to You alone.”