In this paper from a quite experienced group with bacterial adhesion study, they used initial adhesion rate and adhesion numbers after 4h. The number of cells attached increase linearly in the initial phase, which allows a linear fitting to get initial adhesion rate.
Roosjen, A., H. C. van der Mei, H. J. Busscher and W. Norde (2004). "Microbial adhesion to poly(ethylene oxide) brushes: influence of polymer chain length and temperature." Langmuir 20(25): 10949-10955.
Nothing more complex than basic models. No need to go into fancy methods for something already deduced empirically: See http://myxo.css.msu.edu/lenski/pdf/1985,%20AmNat,%20Lenski%20&%20Levin.pdf
I would suggest first t do one step curve of bacteriophage n then proceed for further calculation. one step curve will give you MOI (multiplicity of infection).