Assuming that you want to avoid damaging the tile floor, you would not want to use spikes, unless they are resting on top of the type of footers intended to go underneath spikes/cones (such as the ones made by Mitchell or Quadrapsire, sold by AudioAdvisor), or coins (pennies work OK, although quarters give you a bit more surface area to work with).
You could make a platform from MDF that sits on top of Vibrapods, or a similar isolator, and then place the speaker on top of the platform. Another alternative, which Vandersteen does with speaker stands from SoundAnchors, is to use round-headed machine bolts that screw into the holes provided for the spikes. About 12 years ago, I had a set of Vandy 2Ci's that were used on a tile floor, and I used the machine bolt method -- which seemed to work pretty well.
There is one other factor which may apply: is the tile floor laid on top of a suspended wood floor, or is it on top of a concrete slab floor? If you have a suspended wood floor (as I do in my house), the way you couple/isolate your speakers may change to overall tonal character of your system. You may want to experiment a bit and see which method, either isolation or coupling, yields the kind of overall tonal quality you want.
You could make a platform from MDF that sits on top of Vibrapods, or a similar isolator, and then place the speaker on top of the platform. Another alternative, which Vandersteen does with speaker stands from SoundAnchors, is to use round-headed machine bolts that screw into the holes provided for the spikes. About 12 years ago, I had a set of Vandy 2Ci's that were used on a tile floor, and I used the machine bolt method -- which seemed to work pretty well.
There is one other factor which may apply: is the tile floor laid on top of a suspended wood floor, or is it on top of a concrete slab floor? If you have a suspended wood floor (as I do in my house), the way you couple/isolate your speakers may change to overall tonal character of your system. You may want to experiment a bit and see which method, either isolation or coupling, yields the kind of overall tonal quality you want.