How owners and booking agents share one venue calendar, and who gets told about what.
A venue's calendar is not limited to one person. Two kinds of account can work it, and they are peers — neither outranks the other on a date.
A venue can have both, either, or several representing agents at once. Representation is not exclusive in either direction: an agent books for many venues, and a venue works with many agents. This is also what makes a venue nobody has claimed bookable at all.
By default every open date sits in a shared pool that all of the venue's managers can work. When that gets crowded, a date can be allocated to a specific agent instead.
With several people sharing a calendar, notifying everybody would mean everyone triaging requests meant for a colleague. So a request goes to one person, in this order:
Booking a band that is on RunABand needs that band's consent first — an approved connection with slot requests enabled. Acts with no account here are not affected: they are booked from the venue's own list of acts, or by typing a name. See Your acts.