The courts found Muhammad Ibrahim Tawq and Muhammad Rada Abdullah guilty of trumped-up terrorism charges, and sentenced them to death.
Six other political dissidents were stripped of their nationality as well, Arabic-language Bahrain Mirror reported.
The court also upheld a jail term for the leader of al-Wefaq and former deputy Sheikh Hassan Issa with 10 years' imprisonment in the same case, and sentenced others to prison terms ranging from 6 months to 10 years.
The imprisoned Muslim cleric was charged with funding a "terrorist group" that allegedly carried out a blast in the island of Sitra, located about 12 kilometers southeast of the capital, Manama. Two policemen were killed and 66 others injured in the purported attack.
Thousands of anti-regime demonstrators have held protests in Bahrain on an almost daily basis ever since a popular uprising began in the country in mid-February 2011.
They are demanding justice and relinquishment of the Al-Khalifah regime from power.