Mass spectrometry-based discovery of bacterial immunopeptides presented by infected cells allows untargeted discovery bacterial antigens that can serve as vaccine candidates. Reliable identification of bacterial epitopes by such immunopeptidomics approaches is however challenged by their extreme low abundance. Here, we describe an optimized bioinformatical framework to enhance the confident identification of bacterial immunopeptides. Immunopeptidomics data of cell cultures infected with the foodborne model pathogen Listeria monocytogenes were searched by four different search engines, PEAKS, Comet, Sage and MSFragger, followed by data-driven rescoring with MS2Rescore. Compared to standard single search-engine results, this integrated workflow boosted the number of identified immunopeptides on average by 27% and led to the high confident detection of 18 additional bacterial peptides (+27%) matching 15 different Listeria proteins (+36%). Despite an overall large agreement between the search engines, a small number of conflicts (< 1%) in spectra-to-peptide assignments revealed ambiguous identifications that served as a quality filter. Finally, we show compatibility of our workflow with sensitive timsTOF data acquisition and find that rescoring, now with inclusion of ion mobility features, identifies 76% more peptides compared to orbitrap-based acquisition. Together, our results demonstrate how integration of multiple search engine results along with data-driven rescoring maximizes the identification of immunopeptides, boosting the detection of high confident bacterial epitopes for vaccine development.