TCF ANF is specifically designed to meet the requirements of the French government for naturalisation and gives marks at various levels from beginner right through to completely bilingual. If you get a certain score you get a certificate bearing the magic words "B1", which is all you need.
The test has mandatory sections - comprehension questions and an interview, as well as optional sections - writing. The optional sections are not required for level B1.
Various centres offer this in Bordeaux, including the Alliance Française in the middle of town, and Pat could conceivably take the test in September or October.