I think it depends on how you approach women empowerment.
Alsop et al. (2006) Article Empowerment in Practice: From Analysis to Implementation
develops a framework for assessment empowerment. It combines structural opportunities and agency. The latter refers to the actor's capacity to "make purposeful choices", including different types of assets:
psychological, informational, organizational, material, social, financial, and human assets. It means that to achieve empowerment, women must got a good combination of different types of assets in the support and availability of structural opportunities.
Of course, each factor such as what you propose - joint land titling or women only land title which falls into the category of financial asset - can be important. But the importance must be dependant on how this, joint land titling or female's land titling, contributes to the combination. For instance, joint land titling may help women gain a seemingly equal relationship with their husbands, allowing women to have more confidence (psychological asset), while women's land titling may result in more material possession, making women more powerful compared to their husband. Nevertheless, this is only argument and needs data. Each context, society and situation can provide different evidence for this question.