Right-click an Audio track with Edit Filter set to Audio Transients, and choose 'Add MBT to Pool'. This will give you gridlines (and bonus hideous markers in the timeline) at global snap resolution.
I consider this a workaround because it's awkward and unintuitive to turn on/off, and because of the unecessarily bold and gaudy markers it puts in the timeline. A dedicated TV gridline feature would be preferable. This is one of the oldeset unfulfilled feature requests I can think of.