No, that would be a war crime. You do NOT attack civilian populations. The general trend in history has been towards more protection of civilians. What makes you think Earth would bomb a habitat and murder thousands of people?
You don't have the shoot the city..you cna shoot the dome that hold the manufacturing plants...or organics farms. Force them to surrender by destroying their food and resources...
Mix different purposes together to make it impossible to launch strikes without causing unacceptable civilian casualties, and intercept the Earth fleets before they reach your cities. The United States has been defeated by militarily far weaker powers like Vietnam because those powers made the political consequences of continuing the war not worth it.
Still you'd first need a whole LOT of organic materials... Doubt that would be enough ot feed them all...especialyl it wouldn't be enough to keep htem happy when they have to eat some tastless paste while ppl on Earth eat REAL food.
Astronauts can tolerate nasty preprepared food. People can tolerate many things if there are no alternatives. What are you going to do, starve? Commit treason?
Maby...but still much more vulnerable than any city or structure on Earth. Even a small crack can depressurize the whole thing.
An armored dome would be far, far less vulnerable than an Earth city, as traditional cities are composed of unarmored buildings while the theoretical armored dome would be built to withstand bombardment, like ships are. The ships would have to batter on these armored domes while taking fire from the colonial fleet, orbital weapons platforms, surface-to-space missiles, bombers, etc. Also, air would leak out of a tiny crack in such a large space relatively slowly, giving them time to patch the dome before all the air gets out.