The incident involving a man and a woman, who are known to each other, occurred in the High Street around 11.30pm on Saturday 16 November.
The couple are reported to have exited the William Hardwicke pub shortly before it happened. They then travelled home in a taxi, where their argument continued.
Following enquiries, a 54-year-old man from Bognor was arrested on suspicion of assault occasioning actual bodily harm. He has been bailed with conditions not to contact the woman as the investigation continues.
In the meantime, officers would like to speak to the taxi driver who escorted the couple and anyone who witnessed the incident or intervened.
You can report it online or call 101, quoting serial 35 of 17/11.