No. Both have the same aim, to kill unwanted bacteria, both can be applied together. This will always remain the decision by the physician.
The therapeutic effect of successful antibiotic treatment can be compared with successful phage therapy. The therapeutic aim is achieved when the pathogenic bacterium, this means the individual patient’s strain, is diminished. In both cases of therapy, single resistant bacterial cells might appear. But, while antibiotic resistances will be transferred to the next bacterial generation or to other bacteria by gene transfer and present a risk for future antibiotic therapies, phage therapy has a completely different principle: suitable phages are screened in the single case. Whereas the number of available antibiotic medication products is limited, the number of potential phages is principally unlimited. So, bacterial resistance against phages is not a comparable problem. Because of high phage-host specificity, phages have to be screened against the pathogen, broad-spectrum phages are rare.
In conclusion: bacterial antibiotic resistances have sustainably negative effects, resistances remain persisting, are transferred between bacteria and distributed in the environment. Bacterial resistances against phages play an unimportant role and are not sustainably negative as phages are available in unlimited numbers.