A friend brough back a bottle from the Phillipines. It is 5 years old, more reddish-orange than brown (like a whiskey drink with a shot of Peychaud's in it).
The company's website gives quite a bit of information on how it is made. Both from company info and my taste impressions, I conclude as follows: the company buys distilled alcohol made from sugar (cane or molasses presumably) and ages it in barrels that used to hold whiskey and bourbon. After aging the rum is finished by addition of some sugar and possibly other flavorings.
It's a nice drink, clean, sweetish and quite whiskey-like to my taste (both in flavor and nose). I don't get much rum character such as I associate with Caribbean rums, I think any sugar cane taste is probably effaced by the effects from the ex-whiskey barrels or perhaps by the high proof of the base alcohol.
It is very nice with a slice of lemon or lime.
There are older rums made by the company but I am happy to have this 5 years one which is the drink I am told of the country for those who favor a strong spirit. (It is marked 80 proof and this would seem either to be 40% ABV or higher if the old Sykes system is used for proof measurement in Phillipines).
I'd like to try other types of Tanduay rum but I understand they are hard to find in North America.