I believe T-Bone is still alive.
Moria's been very present in the background, and his arc had Luffy assume a dead dude was just an old man with severe injuries.
T-Bone LOOKS dead, and either faked his death when his assailant thought he died, or allowed the old dude to stab him, because T-Bone is such a bro he told the guy he'd pretend to die so he could get the money to save his family.