The Pothole Action Fund, announced in 2016¸ was for local roads in England outside London, as that has a separate funding arrangement. The other nations of the UK receive a share of any new funding through the Barnett Formula.
For 2020/21, the Pothole Action Fund (£50 million in 2020/21) was combined with the Highways Maintenance Challenge Fund (£100 million) and the new £2.5 billion Potholes Fund announced at Budget 2020 (£500 million). This £650 million funding was allocated by formula, and paid to local highway authorities in England, outside London.
The allocations were published in the Roads Funding Information Pack which is at the following link: https://www.gov.uk/government/publications/roads-funding-information-pack/roads-funding-information-pack.