Police say two suspects threw petrol-filled bottles at Finchley Reform Synagogue but they did not ignite.
It comes a week after the UK government announced it would block the rapper from entering the country.
The 19-year-old was arrested after police identified him as a possible suspect at a court hearing for three other suspects.
A service has not been held in Worcester since 1973, when its Jewish community stopped meeting.
The Mayor of Bath remains suspended after reposting antisemitic conspiracies on social media.
West was due to headline the festival in July but drew criticism over past antisemitic comments.
Wireless Festival has been cancelled by the organisers, after the UK government denied headline act Kanye West permission to enter the country.
Its managing director calls the rapper's past comments "abhorrent" but asks people to "offer some forgiveness".
The rapper's appearance in London in July has caused controversy because of his past antisemitic comments.
