both work and are interchangeable
"Tudo bom" = "All good?" as in "Is everything good?" as in "How are you?"
"Tudo bem" = "All well?" Though you wouldn't say that in English because it doesn't soundd right, in Portuguese, its the same. Same diff. Tanto fais.
or "Tudo ôtimo?" = Is everything awesome? Ôtimo is like Optimum
"Tudo beleza?" = Is everything beautiful? A very nice way to ask.
"E aí cara, tudo bem?" = Sup brah, how's it? Somehow it has a Hawaiian pidgin flare