As I wrote in response to your similar question on July 3:
"Two German auctions in CoinArchives
expand the legend to VOTa Publica SVSCepta PRO SALute ET REDitu Iovi Optimo Maximo SACrata .
"The translation is different from what you thought: "Public vows have been undertaken, holy to Jupiter the Best and Greatest, for the Well-being and the Return (of the Emperor)". The occasion for the vows was Augustus' upcoming departure for Gaul."
It doesn't seem surprising that the vows had been made to Jupiter, the chief god of the Romans.