Little How To to get an Virtual AP running on XBian.
I did NOT choose to install an DHCP Server on Xbian, as I just wanted to use the central one in my network.

1.) Install software

sudo apt-get update  
sudo apt-get install install hostapd hostap-utils iw bridge-utils

2.) Update hostapd

cd ~  
wget http://www.adafruit.com/downloads/adafruit_hostapd.zip  
unzip adafruit_hostapd.zip  
sudo mv /usr/sbin/hostapd /usr/sbin/hostapd.ORIG  
sudo mv hostapd /usr/sbin  
sudo chmod 755 /usr/sbin/hostapd

3.) Configure hostapd
sudo vi /etc/hostapd/hostapd.conf

interface=wlan0  
bridge=br0  
driver=rtl871xdrv  
ssid=MY_SSID  
hw_mode=g  
ieee80211n=1  
channel=11  
macaddr_acl=0  
auth_algs=1  
ignore\_broadcast\_ssid=0  
wpa=3  
wpa\_passphrase=MY\_PASSWORD  
wpa\_key\_mgmt=WPA-PSK  
wpa_pairwise=TKIP  
rsn_pairwise=CCMP

sudo vi /etc/default/hostapd Change

#DAEMON_CONF=""  
to  
DAEMON_CONF="/etc/hostapd/hostapd.conf"  

and save file

4.) Configure hostapd autostart

sudo update-rc.d hostapd enable 

5.) Configure IPv4 Forward
sudo vi /etc/sysctl.conf add

net.ipv4.ip_forward=1  

to the end of the file and save

6.) Configure interfaces
You will need to change the IP address and network to your networks settings!
sudo vi /etc/network/interfaces

auto lo br0  
iface lo inet loopback

iface eth0 inet dhcp  
allow hotplug wlan0  
iface wlan0 inet manual

iface br0 inet static  
bridge-ports eth0 wlan0  
address 192.168.1.75  
netmask 255.255.255.0  
network 192.168.1.0  
broadcast 192.168.1.255  
gateway 192.168.1.1

7.) Configure rc.local for boot
sudo vi /etc/rc.local

add before exit 0

ifup br0  
/etc/init.d/hostapd restart

save and exit

8.) Reboot

sudo reboot

Material used and thanks to:
https://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point/overview
http://www.instructables.com/id/How-to-make-a-WiFi-Access-Point-out-of-a-Raspberry/#step1
https://wiki.debian.org/BridgeNetworkConnections