I got an offer for 100k welcome bonus so I am contemplating if this will be a card I can keep.

When I look at the bonus categories, the electronics category is likely the one I would use the most. But before I commit, I would like to know what stores qualifies for the 4x bonus. I frequently shop at Apple, Best Buy, B&H and Adorama. Also, if I purchase a cell phone from T-Mobile, will it be considered electronics?

TIA