basic.xhtml

    <b:commandButton value="Launch Modal" onclick="#{b:show('modal')}" />

    <b:modal id="modal">

        <f:facet name="header">
            <h3>Facet Header</h3>
        </f:facet>

        <f:facet name="footer">
            <b:commandButton value="Close" onclick="#{b:hide('modal')}" />

            <b:commandButton value="Save Changes" severity="primary" onclick="#{b:hide('modal')}" />
        </f:facet>

        <p>One can define body...</p>

    </b:modal>

BootStrapFunction.java

package org.richfaces.bootstrap.function;

import java.text.MessageFormat;

import javax.faces.component.UIComponent;

import org.ajax4jsf.javascript.ScriptUtils;
import org.richfaces.bootstrap.component.Toggleable;
import org.richfaces.bootstrap.javascript.BootstrapJSPlugin;
import org.richfaces.cdk.annotations.Function;
import org.richfaces.function.RichFunction;

/**
 * @author Lukas Fryc
 */
public final class BootstrapFunction {

    @Function
    public static String toggle(String target) {
        return bootstrapCall(target, Toggleable.class, "toggle");
    }

    @Function
    public static String hide(String target) {
        return bootstrapCall(target, Hideable.class, "hide");
    }

    @Function
    public static String show(String target) {
        return bootstrapCall(target, Showable.class, "show");
    }

    private static String bootstrapCall(String target, Class<?> type, String operationName) {
        UIComponent component = RichFunction.findComponent(target);
        BootstrapOperation operation = new BootstrapOperation(component, operationName);

        operation.verifyComponent(type);
        String call = operation.getCall();
        return call;
    }

    private static class BootstrapOperation {

        private static String CALL = "$('#{0}').{1}('{2}');";
        private static String ESCAPED_CALL = CALL.replace("'", "''");

        private UIComponent component;
        private String operation;

        public BootstrapOperation(UIComponent component, String operation) {
            this.component = component;
            this.operation = operation;
        }

        public String getCall() {
            String clientId = component.getClientId();
            String pluginName = getPluginName();
            String escapedClientId = ScriptUtils.escapeCSSMetachars(clientId);
            return MessageFormat.format(ESCAPED_CALL, escapedClientId, pluginName, operation);
        }

        private void verifyComponent(Class<?> type) {
            if (component == null) {
                throw new IllegalArgumentException("no such target component with identified was found");
            }

            if (component.getClass().isInstance(type)) {
                // TODO unified API for reporting meaningful exceptions (componentID, etc.)
                throw new IllegalArgumentException("the target component " + component + " is not " + type.getName());
            }
        }

        private String getPluginName() {
            BootstrapJSPlugin annotation = component.getClass().getSuperclass().getAnnotation(BootstrapJSPlugin.class);
            if (annotation == null) {
                throw new IllegalArgumentException("given component does not have Bootstrap JavaScript plugin binding defined");
            }
            return annotation.value();
        }
    }
}

• "String escapedClientId = ScriptUtils.escapeCSSMetachars(clientId);" => you need to escape twice to make it works
• ... or you can use RichFunction.jQuerySelector(target)
• ... or remove "$('#{0}')" and replace it with "RichFunction.jQuery(target)