Hey Luka, I would love to pop over for another look in CHC. Really wanna do a proper tour around the south island, maybe in a Britz campervan, or a cycling tour. All good here, work far too busy. Hows it over there and whats news with you?
Basically, just take an ARL Cityline train either way as the Express is less frequent and the time saving is minimal. Timetables and info here, http://srtet.co.th/en/index.html
If your hotel is in Silom you have two options.
ARL Cityline to Phaya Thai station which has a direct pedestrian link to the BTS Phaya Thai station (to answer your query). You then need to change trains at Siam for the Silom line
Or ARL Cityline to Makkasan station which has a pedestrian link to the underground MRT which you can then take to Silom.
Hey mate. Enjoy Wellington. Check out Pravda and Lido Cafes (both favs of mine). Always fun to watch the city go by from Wholly Bagels on Willis Street. And do catch the train to Lower Hutt, its not as bad as we made out ;-)