The parish poll (the DPPT poll was a parish poll) had probably nothing to do with the Localism Bill/Act, and was part of a previous law.
A referendum is intended as binding.
The parish poll was not binding.
The following is a list of cases when a REFERENDUM maybe held as per Localism Act.
Localism Act and Referendums
The Act provides for Referendums to be held for:
Changes to local governance arrangements (i.e. a directly Elected Mayor)
Excessive Council Tax increases
Neighbourhood development orders and the Community Right to Build Order
Persons entitled to vote in these Referendums must be entitled to vote in Local Authority Elections and their names must be included in the relevant Register of Electors.
http://www.boroughofpoole.com/your-council/elections-and-voting/localism-act-and-referendums/