Thermochemical data for either methyl fluoride (CH3F), methyl cation (CH3+), methyl radical (.CH3), fluorine (F), and fluoride ion (F-); can be retrieved from:

M. Kh. Karapet'yants, M. K. Karapet'yants, "Handbook of Thermodynamic Constants of Inorganic and Organic Compounds", Ann Harbour — Humphrey Science Publishers, London, 1970; cf. pp. 89, 303, and 311.

The C−F bond enthalpy (at CH3F) is said to be 552 kJ/mol: https://en.wikipedia.org/wiki/Fluoromethane

Calculation of the reaction enthalpy can either be based on bond enthalpy, or not — depending on the set of thermochemical data actually considered:

CH3F → .CH3 + F → CH3+ + F-