[рони]

lok105,
назначайте autocomplete через цикл

$(function() {
    var user = $("#userName").html();
    $(".pole").each(function(indx, el) {
        $(el).autocomplete({
            source: function(request, response) {
                $.ajax({
                    url: "data.php",
                    dataType: "json",
                    type: "GET",
                    data: {
                        term: el.value,
                        user: user
                    },
                    success: function(data) {
                        response($.map(data, function(item) {
                            return {
                                label: item,
                                value: item
                            }
                        }))
                    }
                })
            },
            minLength: 2
        })
    })
});