You're not actually passing the model to the Partial, you're passing a new ViewDataDictionary<LetLord.Models.Tenant>()
. Try this:
@model LetLord.Models.Tenant
<div class="row-fluid">
<div class="span4 well-border">
@Html.Partial("~/Views/Tenants/_TenantDetailsPartial.cshtml", Model)
</div>
</div>