You could map the array onto an array of objects, like this:
data = $.parseJSON(html);
var items = data.map(function(x) { return { item: x }; });
Then use "labelField" and "valueField" to specify the text/value:
$('#input-tags').selectize({
delimiter: ',',
persist: false,
options: items,
labelField: "item",
valueField: "item"
});