The socialite was spotted with the British royal for several hours last week after attending the premiere of The Dark Knight Rises in London.
The pair were rumoured to have remained close to each other throughout the evening before leaving separately at around 4am.
However, a close friend of Bonas has stated that they are not dating.
"Any rumours there is more to it just isn't true - at least for now," the friend told The Mirror.
"Cressida's shocked there has been such a fuss over all of this. She can't believe she's hit the front pages over simply talking to him. Harry's a flirt but there's nothing going on with them.
"She joked, 'Harry? He's not even my type'. She's heard from him since the news broke and they're both finding it very funny.
"Harry definitely wants there to be a romance and has been pursuing her. But she's playing hard to get. The truth is they've known each other for a long time through friends and they party together."
The aspiring actress is the daughter of social figures Jeffrey Bonas and Lady Mary-Gaye Georgiana Lorna Curzon.
Prince Harry had been spotted on a date with a mystery blonde woman earlier this year.