In my opinion, minimum wage is what you pay total - basic+DA+ allowances, et al. You can break your gross (which should be equal to MW) into basic, DA, allowances in any manner you want, but please ensure that your Basic plus DA portion is at least 50% of the gross and not less.
PF act does not specify that PF is applicable on minimum wages. It only states that PF is applicable on Basic and DA. How do you bifurcate MW is your prerogative. But , ensure that PF is deducted on at leasat 50% of the MW.
Sunder Rajen