The original question is somewhat akin to, "How much wood would a woodchuck chuck if a woodchuck could chuck wood?".
The weapons in question may exist, in one form or another, in some D20 system, but they don't in D&D so all answers are purely speculative.
And you have to ask yourselves you you relate cinematic/real world damage to the D20 system, since everyone knows that D20 damage is anything but realistic.
I know people who are very unhappy that their Star Wars lightsabers aren't just slicing through anything they touch in game. At the same time I remember players in a home-brewed supers campaign sitting in shock when they found out what a .38 pistol does to an unarmored Batman. It all comes down to the grit factor.
Still, to ask about bombs in any form should require some scale. Are we talking Hiroshima- sized bombs, tactical nukes or the cold-war titans? Give me a kilo-ton equivalent, don't just say "Anti-matter bomb". Hiroshima suffered the equivalent of 3 oz. of antimatter being released (6 oz. total matter converted to energy). We've tested bombs several times that size.
And whether it's fission, fusion, anti-matter or plain old chemical, the end result is actually pretty similar, plus or minus radiation.
The way we handled explosions in that supers home-brew was to determine damage at ground zero, then use a simple drop off formula: Measuring from ground zero, lose one point of damage per foot for the first 10 feet. Lose two points per foot for the second 10 feet. Lose three points of damage per foot for the third 10 feet, etc.
The math wasn't as bad as it sounds at first glance, and it gives a playable/credible damage drop off, even if it isn't actually realistic. Shock waves disperse on an inverse-distance squared formula IRL, which call for a lot of math in game and requires a base scale. The points-per-foot method worked pretty cleanly.
To illustrate: A 200 point blast, from 35 feet away loses 10+20+30 for the first 30 feet, plus 20 (5x4) for the last 5 feet. Total damage = 200 - 80.
To compare to D&D: A 10 D6 fireball does 35 points on average. That gives an effective blast radius of about 21.666666 feet.
A 15 dice Delayed Blast Fireball does 52.5 points on average. That works out to a blast radius of about 27.5 feet.
Adds a bit of unpredictability to the ol' precision Fireball maneuver, doesn't it?
IRL bigger bombs don't do proportionally larger areas, they just pulverize ground zero that much more effectively.