"Round tea tray, sweet tea fragrance" may describe the scene of preparing tea at the wedding. Tea trays are used to place tea sets and tea leaves, and poems use "circle" to describe tea trays, which means that the life of new people will be round and full. And "sweet tea is sweet" expresses a sweet and beautiful blessing to a new life.
"Two surnames get married and twins are born at the end of winter" is used to describe the marriage of two people with different surnames, and poetry uses "marriage" to express their union. And "late winter twins" can be understood as they have two children at the end of winter or their lives are twice as rich. This is a good wish for their future life.
Generally speaking, this poem conveys the blessing to the couple and their good expectations for their future life.