Tunnel #1: {192.168.1.0/24}:{Melbourne public IP} {LA public IP}:{10.1.190.0/24}
Tunnel #2: {192.168.254.0/24}:{Melbourne public IP} {LA public IP}:{Internet}
The next step is to SNAT the desired traffic into the second tunnel, so 'Strict routing' must not be selected in the IPsec Connection for Tunnel #2. I think that, instead of a simple SNAT, you can use a 1-to-1 Source NAT to be able to identify the local IP in Melbourne:
1-to-1 NAT : {192.168.1.0/24} -> Web Surfing -> {select IPs} : Map Source to {192.168.254.0/24}
Tunnel #1: {192.168.1.0/24}:{Melbourne public IP} {LA public IP}:{10.1.190.0/24}
Tunnel #2: {192.168.254.0/24}:{Melbourne public IP} {LA public IP}:{Internet}
The next step is to SNAT the desired traffic into the second tunnel, so 'Strict routing' must not be selected in the IPsec Connection for Tunnel #2. I think that, instead of a simple SNAT, you can use a 1-to-1 Source NAT to be able to identify the local IP in Melbourne:
1-to-1 NAT : {192.168.1.0/24} -> Web Surfing -> {select IPs} : Map Source to {192.168.254.0/24}