Can internal bleaching weaken a tooth that underwent root canal treatment?

When i was a kid i fell down and my tooth fractured later as i was aging my tooth started to become a bit discolored.They did root canal treatment,and composite build up of the Fractured part after a year now the tooth became so discolored with a yellowish color. I have a dilemma whether to do internal bleaching or composite vennering. Cant bleaching weaken the tooth more? Since i have a composite restoration,can it be bleached too? Or i go for a composite veneer?