The first thing to understand is the problem is rather complex, TPG have multiple links with 4 providers to USA;
Hurricane Electric
TATA Telecom
Time Warner Telecom.
Cogentco (only seen this in Brisbane so far)
All of these use Southern Cross which has a latency of roughly 145ms syd>sjc when not congested (not including firsthop latency)
Now, to utilize all of this connectivity most ISP's would simply use BGP to balance the traffic load – they would route certain as numbers over different paths in attempt to achieve a decent balance without causing higher latency, this works great because it applies to everyone. If one person has a problem with one path, everyone will, it makes it a snap to determine problems and work around them.
TPG instead barely utilize BGP, and route depending on your IP address – they will simply say, all US based traffic from x.x.x.x/xx routes over this link, end of story.
In theory this works okay and makes it a fair bit easier to balance traffic, but this leads us to another issue that makes problems very hard to diagnose.
TPG HEAVILY utilize MPLS, MPLS is basically what ISP's use to have more control over traffic, without MPLS your traceroutes would be ridiculously long as every device your traffic passes through is shown, and it may end up going where you don't want it.
This means, in 99.99% of cases – what you see outputted when you traceroute to something is fairly inaccurate, TPG is not the only ISP to use MPLS, but they take it to another level, especially if you are tracing something directly connected to their network, ie;
Tracing route to hagg-04-xe-0-2-0.ptld.twtelecom.net [66.193.45.5]
over a maximum of 30 hops:
1 1 ms <1 ms <1 ms 192-168-1-254.tpgi.com.au [192.168.1.254]
2 14 ms 14 ms 15 ms per-pow-stg-bras4-po-2.tpgi.com.au [10.20.21.93]
3 14 ms 14 ms 15 ms per-pow-stg-csw2-po-3.tpgi.com.au [202.7.175.105]
4 205 ms 205 ms 205 ms hagg-04-xe-0-2-0.ptld.twtelecom.net [66.193.45.5]
Trace complete.
This is indicating the Perth core router is connected directly to TPG's transit provider in USA with nothing in-between, obviously not the case – I'd also like to point out from Brisbane, on Telstra you got 191ms whereas me from Perth which introduces alot more latency, is getting 205ms to that. TPG's network is quite honestly fantastic, and they have some of the best connectivity (only Internode is clearly better)... but if you are unfortunate enough to be placed on a congested USA>SJC segment, your going to get pretty poor performance.