I've never worked anywhere that had non-mileage-earning rates. I've worked a couple places that ran flights through the corporate credit card so you never had to float the cash for them (nor did you earn the spend points for them).

In recent years I've worked mainly for medium-sized firms: places where a corp card is offered if you want it, but not mandated. I choose not to use a corp card simply because my volume of travel isn't so high that I would need to worry about credit card bill vs expense reimbursement timing.