When staying at full service brands, Marriott, JW, Renaissance & Autograph hotels you'll receive 10 points per $ on the roomrate and all incidental (ie food and bar) spend. At all other Marriott group hotels points are awarded on roomrate only. No points accrue on taxes.
So a bill of $110 of which $8 is tax will accrue 1020 points (The $102 after tax bill x 10). As you're a silver member you'll qualify for a 20% silver bonus to that amount, that's another 204 points making a total of 1224 points.
Outside USA the points awarded are based on the exchange rate to the $, all the rest of the calculation remains the same.
One last point, only 5 points per $ on roomrate (plus silver 20% bonus) at Townplace suites and Residence Inns...