in most VST instruments, the tempo is controlled by the host (DAW or Cantabile). So they will pick up the tempo you set in Cantabile up here:
The tempo is a per-song setting, so it is saved with the song file, but you can also set it per song state (SongState–>OnLoad binding) or manually tap it by clicking on the note symbol. Tap Tempo can also be assigned to a controller or a note, so if you have a spare button on your keyboard or controller, you can assign that to tap tempo via a binding.
Whatever tempo you have set will be propagated to all synth and effects plugins in you song, so not only arpeggiators will follow the tempo, but also tempo-based delay effects (or you can sync LFOs to host tempo on a number of soft synths if you want to).