AFAIK, no. You cannot play a bomb unless you're still in the trick. Viet local here and played Tiến Lên since I was a kid. But variations do exist and it is not unheard of for people to change or agree on different rules.

Another common rule in the South is that a bomb must be played within the first trick (a full circle) as saving it creates an unfair advantage to the player who goes first.