C. Sawicky,
Your absolute standard of living has, in fact, no bearing on whether you belong to the bourgeoisie or not. It's a question of how you make your money. If you make it through ownership or by abbetting the making of money through ownership, you are a member of the bourgeoisie. The struggling writer scribbling away in obscurity while barely surviving on a small inheritance is a bourgeois. The basketball player who makes a couple million purely as an employee, entertaining the people, is a worker. We pay his boss, his boss pays him.
The question of wealth is less clear-cut but the concept is simple: What kind of wealth is it, personal or extractive? If you own personal property, such as a house, car, that sort of thing, it really makes no difference. The kind of wealth that moves you into the bourgeoise is wealth that puts you in an extractive relationship with your fellow citizen. Stock that is not in your own firm (or if in your own firm, more than an equal share with your fellow employees) clearly makes you a bourgeois. Stock held in a union pension fund is less clear, since the union (in theory anyway) uses its wealth to further the cause of worker rights. The union also represents workers from many different firms. If you own government bonds, I think that is mostly blameless. Corporate bonds are an interesting question: Are they an example of the way in which regular people can use their savings to extract from the corporation, or are they a component in the system of corporate extraction from workers? It's hard to say, but the simplest characterization of the bondholding relationship is that a member of the public is in a contract (not an ownership relationship) to provide working capital and being compensated on a reasonably fair basis. It's not as if the corporation can't easily go elsewhere if it doesn't like your terms. Holders of commodities are, in a sense, waiting for shortage to befall others so they can profit but in the real world, that is not the case. Basic commodities are in adequate abundance and private holders really can't change prices. If you hold gold, antiques, art or some other kind of object fetishized by the bourgeoisie, you are really taking advantage of them, aren't you? Although, it could be said that by participating in bourgeois culture, you are supporting it. I think that is not a strong argument, but a legitimate one. Listening to Wagner doesn't make you a Nazi or an anti-semite, although being a booster of "Wagner culture" might call your values into question.
No matter what kind of wealth she holds, it still is the case that a person who lives on wealth rather than work has different interests than the worker, in general. However, it really does matter what kind of wealth it is because holders of different kind of wealth have different interests. The stockholder always hopes for profit. The bondholder need not hope for profits, only liquidity. The commodity holder prays for shortage but really just hedges against inflation. The holder of fetishized objects hopes that the bourgeoisie will be stupider and more self-involved tomorrow than they are today.