According to this article from TeamViewer website, there are three TCP ports (80, 443 and 5938) used by TeamViewer's latest software.
According to following link, the TeamViewer IP address range is 188.8.131.52/24.
TeamViewer traffic is not web traffic, and thus not seen HTTP/HTTPS traffic by the WSS.
For TeamViewer to work on explicit PAC environment, allow any of these three ports and/or the IP address range at the firewall. TeamViewer traffic is not web traffic and it is not supported through WSS with the Eplicit Proxy access method.
Although TeamViewer might use IE browser setting to send traffic to the WSS data center, this traffic is not seen as web traffic by the WSS and it might or not work. You can work around by adding the destination URL and IP addresses to the Trusted Destination list on the portal. This is disables the protocol detection (and virus/malware scanning) for these destinations because it is non-HTTP and non-SSL, but this is only best effort. You must follow and update the list if TeamViewer decides to change their URL and IP ranges. This is outside scope of work of Blue Coat Support.
Be advised: This might open a possibility of virus/malware infection from these destinations. You must select to accept the risk associated with this method.