FULL PRODUCT VERSION :
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

EXTRA RELEVANT SYSTEM CONFIGURATION :
Windows 7 64bit, NetBeans 8.1 64bit, JDK 1.8.0_74 64bit, JavaFX 8_74

A DESCRIPTION OF THE PROBLEM :
When setting a Tooltip on a Spinner the tooltip only appears when hovering the mouse cursor above the spinner's up and down arrows. The tooltip does not appear when hovering the cursor over the spinner's editor.

Other controls which are built around an editor concept such as ComboBox and DatePicker have their respective tooltip appear correctly whe hovering the mouse above the editor area.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Set a Tooltip on a Spinner and display the spinner in a scene. Hover the mouse cursor above the editor area of the spinner : no tooltip. Now hover the mouse cursor above the arrows areas of the spinner : the tooltip appears.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The tooltip should always appear when hovering the mouse above the editor area.
ACTUAL -
The tooltip never appears when hovering the mouse above the editor area.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public final class SpinnerTooltipBug extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception {
        final ComboBox comboBox1 = new ComboBox();
        comboBox1.setMaxWidth(Double.MAX_VALUE);
        comboBox1.setTooltip(new Tooltip("Combo non-editable toolip."));
        final ComboBox comboBox2 = new ComboBox();
        comboBox2.setEditable(true);
        comboBox2.setMaxWidth(Double.MAX_VALUE);
        comboBox2.setTooltip(new Tooltip("Combo editable toolip."));
        final DatePicker datePicker = new DatePicker();
        datePicker.setMaxWidth(Double.MAX_VALUE);
        datePicker.setTooltip(new Tooltip("DatePicker toolip."));
        final Spinner spinner = new Spinner();
        spinner.setMaxWidth(Double.MAX_VALUE);
        spinner.setTooltip(new Tooltip("Spinner toolip."));
        final VBox root = new VBox(comboBox1, comboBox2, datePicker, spinner);
        root.setStyle("-fx-spacing: 6px; -fx-padding: 6px;");
        final Scene scene = new Scene(root, 500, 400);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String... args) {
        launch(args);
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
The programmer must manually access the editor of the spinner and set the tooltip by hand.