"influential authority" is a correct and usable phrase in written English.
You can use it to refer to a person or group that is powerful, influential, and capable of exercising authority and control over a particular area. For example, "The government has been an influential authority in regulating the economic situation of the country."
A noted anarchist, Comfort wrote numerous works on anarchy, including the highly influential Authority and Delinquency in the Modern State (1950).
He has proved to be the most influential authority in the new Iraq, able to call up huge street protests and get voters to the polls.
Once the chief executive of such a large and influential authority would have been a national figure, opining on matters going well beyond Norwich; striding the big stage.
Even though he has no constituency in the mostly Sunni Kurdish territory, the ayatollah has proved to be the most influential authority in the new Iraq.
Named the most powerful pundit in America by Forbes magazine, and a winner of the Pulitzer Prize, Roger Ebert is inarguably the most prominent and influential authority on the cinema today.
"Hundreds of thousands of people in Britain owe their livelihoods to Kumar Bhattacharyya". Lord Bhattacharyya came to Birmingham from Bangladesh in his 20s and became an influential authority on economic and industrial policy.
His early research on the Army Corps of Engineers in time made him one of the twentieth century's most influential authorities on the planning and development of the nation's water resources.
A number of influential authorities are trying to convert forested area in this region into commercial property (e.g. hotels, plazas, shopping complexes etc).. Therefore, rights of ownership and land tenure arrangements need to be clarified and addressed for the sustainability and conservation of the forest resource.
The moment ministers decide which towns or cities should have HS2 stations and which should not, the chances increase that the unsuccessful councils may join the ranks of those influential authorities including Staffordshire, Warwickshire and now Coventry who unequivocally oppose the entire project.
In Matthew 21 23-32, Jesus confronts some of the highest-ranking, most powerful, and more widely influential authorities within the Judaism of his time and place.
As qigong's detractors in government grew more influential, authorities began attempting to rein in the growth and influence of these groups, some of which had amassed tens of millions of followers.
