All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The reported supplication for the newlyweds is that narrated by Abu Hurayrah that when the Prophet congratulated someone who is getting married, he supplicated for him as follows: “Baaraka Allaahu laka, wa baaraka ‘alayka, wa jama’a baynakuma fee khayr.” (May Allaah bless you and put blessing in you, and may He join you (both) in righteousness.) [Ahmad, Abu Daawood and At-Trimithi]
Besides, Ibn Sa’d and At-Tabaraani in his Al-Kabeer reported a Hadeeth classified by Shaykh Al-Albaani as Hasan that the Prophet supplicated for ‘Ali and Faatimah on the night of their wedding (the night of the consummation of marriage) saying: "Allaahumma baarik feehima wa baarik lahuma fee binaa'ihima" (O Allaah! Bless them, and bless for them their marriage.)
Among the books where you would find these supplications are the books written on marriage and its etiquette like: Aadaab Az-Zifaaf authored by Shaykh Al-Albaani, and Tuhfatul ‘Aroos authored by Al-Istaanbooli, as they are beneficial regarding marriage, its etiquette and its rulings.
Allaah Knows best.