I offer this from a very narrow perspective (I don't know where boilermaker land is
- but in certain cities there are also Hertz Connect options (and others like zipcar) that would work very nicely with a car allowance and limited usage, though suspect that for 30k miles it wouldn't work.
The other opinion I'd offer (imho) is;
Hertz points aren't really worth very much in the long run, I wouldn't really factor them into the cost you are going to be paying Hertz. However, if the scheme is as you descibe it then it sounds pretty useful but sadly I can't offer a view as I've no personal experience.