Plant growth-promoting rhizobacteria (PGPR) can support crop growth and protection, but their performance varies across strains, hosts, soils, and management conditions. Colonization measurements can help explain this variation, although persistence, microbial function, and plant benefit are distinct outcomes. This critical review examines how genome-informed models could prioritize strains for defined colonization tasks. We connect the ecology of dispersal, attachment, competition, and persistence with phenotype measurements, sequence representations, and validation design. Protein language models, DNA-based encoders, pan-genome features, and multi-task learning provide candidate tools, supported mainly by applications to related prediction problems. Their value for strain-level persistence must be assessed against phenotype-based and simpler genomic baselines under matched evaluation conditions. We organize the evidence around three application directions, examine assumptions about laboratory-to-field transfer, functional annotation, and trait independence, and propose a metadata schema and benchmark framework. Independent strain and soil holdouts, endpoint-specific measurements, and prospective field studies are central to assessing added predictive value. The resulting framework is a proposal for testing when genomic information and model complexity improve strain prioritization, with scope determined by the available labels and validation setting.