The agency has also been appointed – alongside content agency Communicator – to deliver a through-the-line campaign, ‘Never Compromise’, for smoothie and juice brand Savsé.
Dullard joined Eulogy as a senior account director in 2016, while Steward signed for the agency as a senior account executive in 2011.
In addition to board responsibilities, Dullard will focus on supporting the corporate comms needs of clients, and Steward will build the agency’s technology offer.
Their promotion follows that of Phil Borge-Slavnich, who was promoted to managing director last August.
Eulogy chief executive Elisabeth Field said: "As we finish our 23rd year, and fourth year of significant growth, we can see the substantial contribution Susie and James have made to helping shape the Eulogy business into the strategic, media savvy creative agency it is today.
"Their promotions reflect the exceptional talent they have, their impact on our business today and their vision for our agency of tomorrow," chief executive Elisabeth Field said.
"We would not be recording such significant growth without them leading the way and I am chuffed to bits that they are joining our Ops Board. It’s just a shame it makes the coffee round bigger."
Eulogy has reported its strongest fiscal year on record, with 15 per cent growth.
This has coincided with the agency expanding its service offering from being a predominantly earned media PR agency to a "business that delivers strategic, creative campaign planning and execution across all channels".
Areas of growth include audio, brand definition, strategy and development, global crisis communications management and reputation management.
The agency’s 62-strong workforce is structured into specialist teams in technology, food and beverage, financial services, automotive, telecoms and health and wellbeing.
In the past year, Eulogy has won several UK and international clients, including Halo Top Creamery, Headspace, Orbitsound, Unidays, Discovery Kids, Oxbotica and Senseon. It has organically grown projects in with retained clients including American Express, Renault, Kantar, Getty Images, Jack Daniel’s, Mizkan and the Civil Aviation Authority.
The most recent of these are Savsé and branding agency Lothar Bohm Associates.
The work with Savsé involves driving awareness and educating people on the unique selling point of its products through an integrated earned media, digital and social-led campaign, alongside Jellybean Creative Solutions, which oversees Savsé’s trade comms.