In the USA there are three distinct types of cards: Personal, Business and Corporate. The distinction between Business and Corporate is based on the size of the firm, not its legal structure. I understand this question to be specifically about "Corporate" cards which are typically issued at large enterprises.
Are there two classes of business-use cards in Australia?
Yes, we also have business and corporate cards, but surely it would contravene a number of laws to hold a corporate employee responsible for company debts, as per previous poster's comments?