Nothing to worry. They have to take some time to verify the signatures as Tanzania is not a member of the Hague
Convention Abolishing the Requirement of Legalisation for Foreign Public Documents. I take it that you got married in Tanzania. The process is fairly long but in short I hope you did it right.
The documents get stamped by RITA in Dar and then get another stamp from the Ministry of Foreign Affairs in Dar. From there they either get legalized in the Spanish Embassy in Tanzania for use in Spain or in Tanzanian Embassy in France (it covers Spain) for use in Spain. So you can see that the verification will have to take a bit of time.
Wishing you a positive response!