This is the e-mail form letter I got after my inquiry to DashBar:

Dear United dash Customer,

Thank you for your inquiry. Your initial sign-up bonus miles are available immediately and will be transfered to your United account the month after you sign-up. All other miles will move from pending to available within 90 days of the end of the month in which the purchase was made. Once available, they will automatically transfer to your United account on the first of the following month.

Please let us know if you have any further questions.

Thank you.

Sincerely,

The dash Customer Service Team