Any process that activates or increases the frequency, rate or extent of protein localization to synapse.
Synonyms:
exact_synonym:
positive regulation of protein localisation to synapse; up regulation of protein localisation to synapse; up regulation of protein localization to synapse; upregulation of protein localisation to synapse; upregulation of protein localization to synapse
narrow_synonym:
activation of protein localisation to synapse; activation of protein localization to synapse