So I should spend an average of £60 per week over the qtr running May - June - July to get premier status for Aug - Sept - Oct.

It is not likely that my points for the Life Assurance will be credited to the Tesco Clubcard account by mid April. So by operating this tactic, it will enable me to credit the points I receive by middle of July (hopefully all the Life Assnce points are through by then) to the BA account whilst premier during the Aug to Oct qtr.