Most herbicides made for residential use are generally considered to be safe for use in environments where animals frequent, as long as the label instructions are followed exactly. For example, if a weed killer spray label states, "Keep animals away from treated areas until dry," it is important to adhere to these instructions in order to avoid problems. If these instructions are not followed, affected animals might exhibit such symptoms as mild skin or gastrointestinal irritation, or the desirable vegetation could be damaged from unintentional spread of the herbicide.
Since your situation involves nesting wild rabbits who cannot be as easily kept away from treated areas as can a dog or cat, we would first suggest putting up a temporary barricade around the nest (using wire garden fencing or something similarly appropriate) to keep the rabbits safely enclosed while the yard is being treated. We would also advise that the lawn company avoid applying the fertilizer and herbicide in close proximity to the nest to avoid unintentional overspray. The barricade should be kept in place to keep the rabbits off the lawn for a few hours to allow the treated areas time to dry. Once the treated areas are dry, we would not anticipate problems from the rabbits having contact with the lawn.