Those who voted in favour were Simon O'Donoghue, Gary Caffell, Pip Hannon, Chris Peterson, David Holmes and Graham McClymont.
Mayor Lyn Patterson was also in favour.
Wairarapa's regional development contribution is around $250,000 so the council would be seeking a commitment to have $125,000 returned for spending in Wairarapa.
Councillors were in agreement when it came to assessing the input from Wairarapa in terms of WREDA's expected overall budget which could amount to $44 million a year, acknowledging Wairarapa is a "bit player" whose decision was unlikely to alter the thinking of those on the other side of the Rimutaka Hill.
Councillor Chris Peterson at one stage referred to Wairarapa as being "the mouse that roared" on this issue.
Wairarapa would have a single representative on the committee which would oversee WREDA from a political viewpoint, as would Upper Hutt City, Lower Hutt City, Porirua City, Kapiti District Council and Greater Wellington Regional Council. Wellington City Council would have four representatives.
Wellington advocates of a single economic agency claim the benefits will include stronger economic leadership and the advantage of having one voice to lobby central government, business investors and research providers.