The property values during the bonus game have new random multipliers (buildings) applied each new bonus round.
Like you LD, I’m not the most frequent player of big wheel games. But as I recall any additional (ie. Chance) multiplier is applied at this initial (property building) stage, rather than to your winnings after. Such that only your initial bet appears doubled (in Littlerobot’s case).
.... with your winnings being the sum of all the squares/properties (multipliers) & minus any deductions (Tax etc.) you land on via the dice rolls.
...... hopefully that’s a tad more clear than the house rules
Having the additional Chance multiplier applied to the bonus round property squares before the dice rolls clearly makes sense from an excitement sense. Players hoping to land on the inflated multipliers with each dice roll.