Luna: <Quirks a brow as she looks over one> And with astonishing adherence to the rules for writers one might note... also rather interesting additions to thine undercarriage... <blushes>
Celestia: Additions to my what <looks at scroll> OH EW! <faints>
Luna: <looks one way, then another, then inconpicuously hides the scrolls under a wing>
Not under our law. But being a Wonderbolt isn't how Rainbow Dash makes her living: she works for the Ponyville government controlling the local weather.
The stipend would be a bonus income given to Wonderbolt members. And between the demanding requirements and the fact that most members are already in the Equestrian regular military or join it later, a Wonderbolt that can't get an adequate job or income source without the stipend would be very odd indeed.
Besides, I interpreted you original comment as surprise they even got paid since they're usually shown doing little but the odd stunt show. I was just saying that they deserved some compensation.
In Baron-Engel's version of Equestria, the Element bearers are formally acknowledged as major strategic assets of the Crown. Each received a royal stipend to ensure they remained happy and could afford to leave work whenever they were called on. After a flurry of bets were placed on an event against Rainbow Dash and she came through, the winner gifted her with a very large sum and her stipend was cancelled as unnecessary.
I don't know the status of the other stipends. They were probably at least reduced when the Elements were returned to the Tree of Harmony, but restored when the Mane Six effectively became Twilight's 'Round Table' and showed their unique relationship with that map in her castle.