Cisco QoS to use spare capacity

Hi,
I'm working on a qos config for a cisco. The scenario is as follows:

We provide a 100Mb service into a premises.
Several IP networks are routed to the premises.
We'd like to allocate 90% of the bandwidth to 192.168.50.0 /24 & the remainder to the following network - 10.10.10.0/24

I have the following config so far, which is limiting the 192.168.150.0/24 network to about 90% and also applying the limit to the 10.10.10.0/24 network, but it doesn't appear that the 10.1.1.0/24 network can utilize the 'spare' bandwidth when it isn't being used by 192.168.50.0/24

Can anyone offer some suggestions or better ways to achieve the same outcome?
btw the below config is being applied to the customer's upstream router on a sub-interface (our router)

class-map match-any customer-1
match access-group 100
class-map match-all data
match access-group 150

policy-map bw-reserve
class customer-1
priority percent 90
class data
priority percent 10

policy-map qos-voip-parent
class class-default
shape average 20000000
service-policy bw-reserve


interface FastEthernet0/0.10
description link to the customer QoS applied here
bandwidth 100000
encapsulation dot1Q 10
ip address 172.16.20.1 255.255.255.252
service-policy output qos-voip-parent

access-list 150 remark Normal ip data traffic to all other hosts
access-list 150 permit ip any any
access-list 100 remark Allow up to 90% or bandwidth for customer-1
access-list 100 permit ip any192.168.50.0 0.0.0.255

Thanks in advance,
Jonathan