Can I attach two of these to the bottom of my TV to compliment the gradient light strip
Should be able to. There’s a two-pack for sale here that includes an adapter that looks like you can plug three Hue things into.
The the Hue Play Bar lights are able to be synced up with the various light strips (whether through the Hue sync HDMI box, or other methods, like through Signal RGB or a few different programs).
However, this particular product sale is for a single light bar extension - It does not include the base kit, with the power adapter. If you choose a base kit, those are able to accept up to a maximum of three of these lights per plug (physical limit on the power adapter). They are extremely easy to pair and get running though. And again, also easy to sync with other lights, whether for music or movies.
Hope that helps.