How to determine bounding rectangle for obscured locations?

Given an obscured location, I’d like to determine the bounding rectangle of its possible location. The help page describes that it will be placed within a 0.2 x 0.2 degree cell. Are these cells fixed at regular intervals of .0, .2, .4, .6 or .8 degrees from a whole number?

For example, a location of -41.284333, 174.703537 would be within the bounding rectangle -41.2, 174.6; -41.2, 174.8; -41.4, 174.8; -41.4, 174.6?

The reason for wanting to determine this is to restrict the possible location of the observation to approx 400 km2, as opposed to approx 2300 km2 if we draw a circle with radius of a location accuracy figure of approx 27km from its obscured location. We’re building an application that assigns the observations to regions and this will limit the potential regions the observation is assigned to.