The 794 bus stops at the museum door, but we couldn't see the 794 bus stop at the metro station so, having read that it's an 800 metre walk, we decided to go on foot. Lucky we had a map because there are no signs anywhere to keep you on the right track. Leave the metro station on the Line 1 side, turn right and just keep walking, under the Vasco da Gama bridge, until you see the convent gates. The entry is off the road on the lower side. It took us about 15 minutes, the chapel alone is well worth the walk, the tiles are very interesting, and we had a very nice inexpensive snack lunch at the restaurant/café.
If you own or manage National Tile Museum, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.