Bright Sky Events managing director Mike Prosser said the agency is expecting to see a further 30% growth in turnover for the year ending February 2013.
Bentley was formerly national agency sales manager at Q Hotels.
Her new role will focus on developing new business for the agency.
"We have had a very successful couple of years in which we have doubled our turnover and we felt we wanted to keep the momentum going," said Prosser.
"The only way to do this was to expand our business and bring in someone with events industry sales experience who could add value. We will be expanding the team later this year once Alyson wins us some new accounts."