"This unbreakable bunker stands as the most amazing symbol of the victory of humanity against the infected. It's a beacon of hope and courage for everyone in the colony."
Theoretically, the Victorious can cover 514 dwellings, but in reality this number will usually be limited by terrain and practicality. Assuming theoretical maximum of stone houses, it pays for its gold investment in:
(7000 + 7000) / (514 * 40 * 0.2 - 120) ~= 3.5 ticks, or 28 hours.
Usually 150 stone houses is enough to beat most maps. Assuming this more practical benchmark:
(7000 + 7000) / (150 * 40 * 0.2 - 120) ~= 12.96 ticks, or 4 days 8 hours.
This means usually just building more Stone Houses gives better return on investment. Consider building this wonder if there is either no safe space available or there is a risk of hitting resource cap, and there is considerable time until final wave.
This is mostly flavor. Don't use the Victorious as a wall. While it has high defenses life, it also has wide surface, meaning infected can surround it (unless you found a choke point that it fits perfectly).