Among the things you can depend on in this life is Jean-Pierre. The cuisine is dependably good, the menu is dependably traditional, the dining room is dependably dull looking, and the service is dependably . . . erratic. To start, as one should, with the food, Jean-Pierre does very well by its standards - rich, spicy lobster bisque, veal pale and elegant in rich cream-and-mush-room sauces, lamb chops beautifully trimmed and cooked and cleverly dressed with green peppercorn cream sauce. To their credit, the seasonings tend to be splashy - a great deal of mustard in the grilled rockfish with mustard cream. But they occasionally over-reach, as in the slightly cloying vension grand veneur. The timing of the heat turns out flawless. But the timing in the dining room can leave you waiting for an hour for your appetizer or grabbing your waiter to ask what the day's specials are before he disappears at a run. Jean-Pierre is one of the only top French restaurants willing to take an 8 p.m. reservation rather than insisting on 7 and 9:30 p.m. seatings, and for that it may be worth putting up with the mid-evening rush to have a chance to linger over coffee without being pressured for your seat. I would recommend that a redecoration be considered, but the last one - plaid wallpaper in autumn colors - only made things worse. So it remains things worse. So it remains a graceless room with considerable bustle and little space between the tables. But usually the service is not only professional, but personable, and care is taken with details such as salads, cheeses and desserts. If the wine list - broad and fairly interesting, more expensive than average - does not tempt you, ask for the special list of red wines - mostly '66s - which are higher priced but better buys and exceedingly tempting. If Jean-Pierre has been upstaged by more extravagant competition, its prices are slightly less extravagant than theirs, and it remains as good as it has always been, which is very good.